Perhaps because the OT and NT explain what God was doing to work His plan of salvation (POS) from creation to Christ,
we understand that the purpose of OT history through the revelation of Revelation was to provide/reveal Messiah for the
potential salvation of sinful humanity, but what do you think God was doing from circa 100-1000 A.D.?
From c. 100-1000 AD it appears that God was allowing three main things to occur:
1. Most of the world remained ignorant of the OT-NT and were dependent on general revelation for salvation.
2. Much of the world was conquered by anti-Christian Muslims.
3. Much of Europe was converted to corrupt Catholicism.
This was indeed a dark age, ignorant of the true apostolic Gospel (
“Accept Christ Jesus as Lord” as in Acts 16:31, 2Cor. 4:5 & Col. 2:6) or “Love Jesus as Messiah and Lord” (John 8:42), which can be elaborated as follows:
1. There is a/one all-loving and just Lord or
God (Deut. 6:4, John 3:16, 2Thes. 1:6), who is both able (2Tim. 1:12) and willing (1Tim. 2:3-4, Ezek. 33:11) to provide all morally accountable human beings salvation or heaven—a wonderful life full of love, joy and peace forever.
2.
Human beings are selfish or sinful (Rom. 3:23, 2Tim. 3:2-4, Col. 3:5), miserable (Gal. 5:19-21), and hopeless (Eph. 2:12) or hell-bound at the judgment (Matt. 23:33 & 25:46) when they reject God’s salvation (John 3:18, Rom. 2:5-11).
3. Jesus is God’s
Messiah/Christ and incarnate Son, the way that God has chosen (John 3:16, Acts 16:30-31, Phil. 2:9-11) of providing salvation by means of his atoning death on the cross for the payment of the penalty for the sins of humanity (Rom. 3:22-25 & 5:9-11), followed by his resurrection to reign in heaven (1Cor. 15:14-28).
4. Thus, every person who perceives God’s moral nature or hears the NT
Gospel needs to repent and accept God’s justification in Jesus as Christ/Messiah the Lord or Supreme Commander (Luke 2:11, John 14:6, Acts 16:31), which means trying to obey (Phil. 3:12, 1John 1:8) His commandment to love one another (Matt. 22:37-40, John 13:35, Rom. 13:9)—forever (Matt. 10:22, Psa. 113:2).
5. Then God’s
Holy Spirit will establish a saving relationship with those who freely accept Him (Rev. 3:20) that will eventually achieve heaven when by means of persevering in learning Truth/God’s Word/sanctification everyone cooperates fully with His will (John 14:6, 17&26, Rom. 8:6-17, Gal. 6:7-9, Eph. 1:13-14, Heb. 10:36, 12:1, Jam. 1:2-4). Such cooperation can be termed “the surrendered life”.
6. This creed summarizes revelation of the NT Gospel/Truth (Matt. 26:13, John 14:6), which fulfilled the OT revelation (Matt. 5:17, John 19:30, Heb. 7:11-10:10) and culminates the search for salvation by souls who know only
general revelation (Rom. 1:20, 2:14-16, Matt. 7:12). Seeking begins when souls love truth/repent of false beliefs (2Thes. 2:10&13, Matt. 4:17, 7:7), which is the Way to eternal life God wills, who is the Lord Jesus (Matt. 7:14, John 1:14, 4:24, 14:6). Lacking this love leads to believing lies and debauchery (Matt. 7:6, Rom. 1:18&25-26, 2Thes. 2:11-12).