The resurrection of Christ from the dead is a Gospel Truth, it was Preached in the OT and understood to a degree in the OT. Job knew of the resurrection when He stated this Job 19:25
For I know that my redeemer liveth, and that he shall stand at the latter day upon the earth:
Jesus said His Death and Resurrection was fulfillment of Scripture from the OT
scriptures !
1 Cor 15:3-4
3 For I delivered unto you first of all that which I also received, how that Christ died for our sins according to the scriptures;
4 And that he was buried, and that he rose again the third day according to the scriptures:[/B]
God Preached the Gospel, the same Gospel to Abraham saying Gal 3:8
8 And the scripture, foreseeing that God would justify the heathen through faith, preached before the gospel unto Abraham, saying, In thee shall all nations be blessed.