It is often claimed that protestant doctrine and biblical interpretation has changed and different interpretations have come about since the Reformation, which is true. The pre-tribulation rapture idea is one such example. And there's countless others to do with pre millenialism etc.
Yet it should be recognised that the same or similar sorts of doctrinal changes have also occured within the claimed apostolic churches, Roman Catholic, the Orthodox and their variants , Church of England (episcopal/anglican), often with their denial of such changes ever taking place. "We have always believed these things to be so" is the claim. Or it is claimed that doctrine needs to be developed. I see no difference between the development of a Roman Catholic belief in purgatory and indulgences (which are not found in canonical scripture), and the development of a pre-tribulation rapture idea within protestant theology.
A nice list can be found below of the introduction of new traditions , practices, doctrines, observations etc within the Catholic church.
Not all of these may be doctrines, but more traditions or observances. Still, what should be clear is that doctrinal, traditional or observational changes within the Church, whether it be Roman Catholic, Orthodox, Protestant or whatever, happens over time. Within the apostolic churches in recent times, it has been the issues of homosexuality, evolution, greater acceptance of Muslims and protestants, contraception, abortion, ordination of female priests which have been hot topics. Given the record of history it is hard to deny changes taking place in both doctrine, tradition and practice. The Roman Catholic and pre-tribulation believer alike appear foolish in claiming "these things have always been so" when the historical records are self-evident.
http://www.bible.ca/cath-new-doctrines.htm
200 AD
Immersion of infants who are dying, but considered sinless. (Tertullian V.12)
250 AD
North Africa region is first to practice infant baptism and reduced the age of baptism from minors to all newborns. This is opposed by other regions.
257 AD
Baptism by sprinkling for adults instead of immersion first used as an exception for those on sick beds, but it caused great dispute.
300 AD
Prayers for the dead
320 AD
Special dress code of the clergy in worship
325 AD
At the general council of Nice, 325, it was proposed indeed, probably by the Western bishop Hosius, to forbid entirely the marriage of priests; but the motion met with strong opposition, and was rejected.
325 AD
The date for Easter was set.
379 AD
Praying to Mary & Saints. (prayers of Ephraim Syrus)
385 AD
In the West, the first prohibition of clerical marriage, which laid claim to universal ecclesiastical authority, proceeded in 385 from the Roman church in the form of a decretal letter of the bishop Siricius to Himerius, bishop of Tarragona in Spain.
389 AD
Mariolatry begins with Gregory Nazianzen, who mentions in a eulogy, how Justina had besought the virgin Mary to protect her virginity.
400 AD
Impossibility of apostasy or once saved always saved, (Augustine XII.9)
416 AD
Infant baptism by immersion commanded of all infants (Council Of Mela, Austin was the principal director)
430 AD
Exhalation of Virgin Mary: "Mother of God" first applied by the Council of Ephesus
502 AD
Special dress code of the Clergy all the time.
500 AD
The "Habit" of Nuns (Black gowns with white tunics)
519 AD
Lent
526 AD
Extreme Unction
593 AD
The Doctrine of Purgatory popularized from the Apocrypha by Gregory the Great
600 AD
First use of Latin in worship (Gregory I)
Beginning of the Orthodox/Roman Catholic church as we know it today in its present organization.
607 AD
First Pope: Boniface III is the first person to take the title of "universal Bishop" by decree of Emperor Phocas.
608 AD
Pope Boniface IV. turns the Pantheon in Rome into a temple of Mary ad martyres: the pagan Olympus into a Christian heaven of gods.
670 AD
Instrumental music: first organ by Pope Vitalian
709 AD
Kissing of Pope Constantine’s feet
753 AD
Baptism by sprinkling for those on sick beds officially accepted.
787 AD
Worship of icons and statue approved (2nd council of Nicea)
787 AD
Rome (Latin) and Constantinople (Greek) part ways and begin the drift towards complete split, resulting in two denominations emerging in 1054 AD.
965 AD
Baptism of bells instituted by Pope John XIII
850 AD
Burning of Holy Candles
995 AD
Canonization of dead saints, first by Pope John XV
998 AD
Good Friday: fish only and the eating-red meat forbidden
1009 AD
Holy water
1022 AD
Penance
1054 AD
Roman Catholic church breaks away from the Orthodox church
1054 AD
Roman Catholics officially embrace instrumental music, Orthodox reject instrumental music down to the present time.
1079 AD
Celibacy enforced for priests, bishops, presbyters (Pope Gregory VII)
1090 AD
Rosary beads: invented by Peter the Hermit
1095 AD
Instrumental music
1190 AD
Sale of Indulgences or "tickets to sin" (punishment of sin removed)
1215 AD
Transubstantiation by Pope Innocent III, Fourth Lateran Council
1215 AD
Auricular Confession of sins to priests instituted by Pope Innocent III, (Lateran Council)
1215 AD
Mass a Sacrifice of Christ
1217 AD
Adoration and Elevation of Host: ie. communion bread (Pope Honrius III)
1230 AD
Ringing bells at Mass
1251 AD
The Scapular, the brown cloak worn by monks invented by Simon Stock
1268 AD
Priestly power of absolution
1311 AD
Baptism by sprinkling accepted as the universal standard instead of immersion for all, not just the sick. (Council of Ravenna)
1414 AD
Laity no longer offered Lord's cup at communion (Council of Constance)
1439 AD
Purgatory a dogma by the Council of Florence (see 593 AD)
1439 AD
Doctrine of Seven Sacraments affirmed
1480 AD
The Inquisition (of Spain)
1495 AD
Papal control of marriage rights
1534 AD
Order of Jesuits founded by Loyola
1545 AD
Man-made tradition of church made equal to Bible (Council of Trent)
1545 AD
Apocryphal books added to Bible (Council of Trent)
1546 AD
Justification by human works of merit
1546 AD
Mass universally said in Latin (see 600 AD)
1547 AD
Confirmation
1560 AD
Personal opinions of Pope Pius IV imposed as the official creed
1864 AD
Syllabus Errorum [Syllabus of Errors] proclaimed that "Catholic countries" could not tolerate other religions, (no freedom of religion), conscience, separation of church and State condemned, asserted the Pope's temporal authority over all civil rulers (Ratified by Pope Pius IX and Vatican Council) condemned
1870 AD
Infallibility of Pope (Vatican council)
1908 AD
All Catholics should be christened into the church
1930 AD
Public Schools condemned by Pope Pius XII (see 1864 AD)
1950 AD
Sinners prayer, invented by Billy Sunday and made popular by Billy Graham. (Some Catholics now use this)
1950 AD
Assumption of the body of the Virgin Mary into heaven shortly after her death. (Pope Pius XII)
1954 AD
Immaculate conception of Mary proclaimed by Pope Pius XII
1995 AD
The use of girls in the traditional alter boy duties
1996 AD
Catholics can believe in Evolution (Pope John Paul II)
Yet it should be recognised that the same or similar sorts of doctrinal changes have also occured within the claimed apostolic churches, Roman Catholic, the Orthodox and their variants , Church of England (episcopal/anglican), often with their denial of such changes ever taking place. "We have always believed these things to be so" is the claim. Or it is claimed that doctrine needs to be developed. I see no difference between the development of a Roman Catholic belief in purgatory and indulgences (which are not found in canonical scripture), and the development of a pre-tribulation rapture idea within protestant theology.
A nice list can be found below of the introduction of new traditions , practices, doctrines, observations etc within the Catholic church.
Not all of these may be doctrines, but more traditions or observances. Still, what should be clear is that doctrinal, traditional or observational changes within the Church, whether it be Roman Catholic, Orthodox, Protestant or whatever, happens over time. Within the apostolic churches in recent times, it has been the issues of homosexuality, evolution, greater acceptance of Muslims and protestants, contraception, abortion, ordination of female priests which have been hot topics. Given the record of history it is hard to deny changes taking place in both doctrine, tradition and practice. The Roman Catholic and pre-tribulation believer alike appear foolish in claiming "these things have always been so" when the historical records are self-evident.
http://www.bible.ca/cath-new-doctrines.htm
200 AD
Immersion of infants who are dying, but considered sinless. (Tertullian V.12)
250 AD
North Africa region is first to practice infant baptism and reduced the age of baptism from minors to all newborns. This is opposed by other regions.
257 AD
Baptism by sprinkling for adults instead of immersion first used as an exception for those on sick beds, but it caused great dispute.
300 AD
Prayers for the dead
320 AD
Special dress code of the clergy in worship
325 AD
At the general council of Nice, 325, it was proposed indeed, probably by the Western bishop Hosius, to forbid entirely the marriage of priests; but the motion met with strong opposition, and was rejected.
325 AD
The date for Easter was set.
379 AD
Praying to Mary & Saints. (prayers of Ephraim Syrus)
385 AD
In the West, the first prohibition of clerical marriage, which laid claim to universal ecclesiastical authority, proceeded in 385 from the Roman church in the form of a decretal letter of the bishop Siricius to Himerius, bishop of Tarragona in Spain.
389 AD
Mariolatry begins with Gregory Nazianzen, who mentions in a eulogy, how Justina had besought the virgin Mary to protect her virginity.
400 AD
Impossibility of apostasy or once saved always saved, (Augustine XII.9)
416 AD
Infant baptism by immersion commanded of all infants (Council Of Mela, Austin was the principal director)
430 AD
Exhalation of Virgin Mary: "Mother of God" first applied by the Council of Ephesus
502 AD
Special dress code of the Clergy all the time.
500 AD
The "Habit" of Nuns (Black gowns with white tunics)
519 AD
Lent
526 AD
Extreme Unction
593 AD
The Doctrine of Purgatory popularized from the Apocrypha by Gregory the Great
600 AD
First use of Latin in worship (Gregory I)
Beginning of the Orthodox/Roman Catholic church as we know it today in its present organization.
607 AD

608 AD
Pope Boniface IV. turns the Pantheon in Rome into a temple of Mary ad martyres: the pagan Olympus into a Christian heaven of gods.
670 AD
Instrumental music: first organ by Pope Vitalian
709 AD
Kissing of Pope Constantine’s feet
753 AD
Baptism by sprinkling for those on sick beds officially accepted.
787 AD
Worship of icons and statue approved (2nd council of Nicea)
787 AD
Rome (Latin) and Constantinople (Greek) part ways and begin the drift towards complete split, resulting in two denominations emerging in 1054 AD.
965 AD
Baptism of bells instituted by Pope John XIII
850 AD
Burning of Holy Candles
995 AD
Canonization of dead saints, first by Pope John XV
998 AD
Good Friday: fish only and the eating-red meat forbidden
1009 AD
Holy water
1022 AD
Penance
1054 AD
Roman Catholic church breaks away from the Orthodox church
1054 AD
Roman Catholics officially embrace instrumental music, Orthodox reject instrumental music down to the present time.
1079 AD
Celibacy enforced for priests, bishops, presbyters (Pope Gregory VII)
1090 AD
Rosary beads: invented by Peter the Hermit
1095 AD
Instrumental music
1190 AD
Sale of Indulgences or "tickets to sin" (punishment of sin removed)
1215 AD
Transubstantiation by Pope Innocent III, Fourth Lateran Council
1215 AD
Auricular Confession of sins to priests instituted by Pope Innocent III, (Lateran Council)
1215 AD
Mass a Sacrifice of Christ
1217 AD
Adoration and Elevation of Host: ie. communion bread (Pope Honrius III)
1230 AD
Ringing bells at Mass
1251 AD
The Scapular, the brown cloak worn by monks invented by Simon Stock
1268 AD
Priestly power of absolution
1311 AD
Baptism by sprinkling accepted as the universal standard instead of immersion for all, not just the sick. (Council of Ravenna)
1414 AD
Laity no longer offered Lord's cup at communion (Council of Constance)
1439 AD
Purgatory a dogma by the Council of Florence (see 593 AD)
1439 AD
Doctrine of Seven Sacraments affirmed
1480 AD
The Inquisition (of Spain)
1495 AD
Papal control of marriage rights
1534 AD
Order of Jesuits founded by Loyola
1545 AD
Man-made tradition of church made equal to Bible (Council of Trent)
1545 AD
Apocryphal books added to Bible (Council of Trent)
1546 AD
Justification by human works of merit
1546 AD
Mass universally said in Latin (see 600 AD)
1547 AD
Confirmation
1560 AD
Personal opinions of Pope Pius IV imposed as the official creed
1864 AD
Syllabus Errorum [Syllabus of Errors] proclaimed that "Catholic countries" could not tolerate other religions, (no freedom of religion), conscience, separation of church and State condemned, asserted the Pope's temporal authority over all civil rulers (Ratified by Pope Pius IX and Vatican Council) condemned
1870 AD
Infallibility of Pope (Vatican council)
1908 AD
All Catholics should be christened into the church
1930 AD
Public Schools condemned by Pope Pius XII (see 1864 AD)
1950 AD
Sinners prayer, invented by Billy Sunday and made popular by Billy Graham. (Some Catholics now use this)
1950 AD
Assumption of the body of the Virgin Mary into heaven shortly after her death. (Pope Pius XII)
1954 AD
Immaculate conception of Mary proclaimed by Pope Pius XII
1995 AD
The use of girls in the traditional alter boy duties
1996 AD
Catholics can believe in Evolution (Pope John Paul II)