Even though the Gospel is quite simple, it continues to be misunderstood and/or misrepresented. Many people are not sure to this day whether salvation is by grace through faith in Christ and His finished work of redemption, or whether baptism is necessary for salvation, or perhaps other good works, or the sacraments, are necessary for salvation. Then there are some who claim that God arbitrarily elects some for salvation, and others for damnation (which would be a violation of the character of God as well as a travesty of the Gospel). Therefore we need to be clear from Scripture are to what exactly is the Gospel, and how God saves sinners purely by His grace.
1. Christ Jesus came into the world to save sinners: This is a faithful saying, and worthy of all acceptation, that Christ Jesus came into the world to save sinners; of whom I am chief. (1 Tim 1:15)
2. God sent His Son into the world so that the whole world of humanity would be saved: For God sent not his Son into the world to condemn the world; but that the world through him might be saved. (John 3:17)
3. Sinners are saved by believing on the Lord Jesus Christ and calling upon the Name of the Lord: And [he] brought them out, and said, Sirs, what must I do to be saved? And they said, Believe on the Lord Jesus Christ, and thou shalt be saved, and thy house... [no mention of baptism at this point, but baptism must follow immediately, as seen in the next few verses]
That if thou shalt confess with thy mouth the Lord Jesus, and shalt believe in thine heart that God hath raised him from the dead, thou shalt be saved. For with the heart man believeth unto righteousness; and with the mouth confession is made unto salvation. For the scripture saith, Whosoever believeth on him shall not be ashamed. For there is no difference between the Jew and the Greek: for the same Lord over all is rich unto all that call upon him. For whosoever shall call upon the name of the Lord shall be saved. (Acts 16:30,31; Rom 10:9-13).
4. The Gospel is the Good News that Christ died for our sins and rose again for our justification: Moreover, brethren, I declare unto you the Gospel which I preached unto you, which also ye have received, and wherein ye stand; By which also ye are saved, if ye keep in memory what I preached unto you, unless ye have believed in vain. For I delivered unto you first of all that which I also received, how that Christ died for our sins according to the scriptures; And that he was buried, and that he rose again the third day according to the scriptures... And therefore it was imputed to him [Abraham] for righteousness. Now it was not written for his sake alone, that it was imputed to him; But for us also, to whom it shall be imputed, if we believe on him that raised up Jesus our Lord from the dead; Who was delivered for our offences, and was raised again for our justification. (1 Cor 15:1-4; Rom 4:22-25)
5. We are saved (justified) by grace through faith in Christ alone, and His finished work of redemption, not by works of righteousness which we have done: Therefore being justified by faith, we have peace with God through our Lord Jesus Christ: By whom also we have access by faith into this grace wherein we stand, and rejoice in hope of the glory of God... For by grace are ye saved through faith; and that not of yourselves: it is the gift of God: Not of works, lest any man should boast. (Rom 5:1,2; Eph 2:8,9)
6. Repentance is necessary for the remission of sins and for salvation: And [Christ] said unto them, Thus it is written, and thus it behoved Christ to suffer, and to rise from the dead the third day: And that repentance and remission of sins should be preached in his name among all nations, beginning at Jerusalem... Then Peter said unto them, Repent, and be baptized every one of you in the name of Jesus Christ for the remission of sins, and ye shall receive the gift of the Holy Ghost... Repent ye therefore, and be converted, that your sins may be blotted out, when the times of refreshing shall come from the presence of the Lord... And the times of this ignorance God winked at; but now commandeth all men every where to repent (Lk 24:46,47; Acts 2:38; 3:19; 17:30).