"Now I am making known to you, brethren, the evangel which I bring to you, which also you accepted, in which also you stand, through which also you are saved, if you are retaining what I said in bringing the evangel to you, outside and except you believe feignedly. For I give over to you among the first what also I accepted, that Christ died for our sins according to the scriptures, and that He was entombed, and that He has been roused the third day according to the scriptures, and that He was seen by Cephas, thereupon by the twelve. Thereupon He was seen by over five hundred brethren at once, of whom the majority are remaining hitherto, yet some were put to repose also. Thereupon He was seen by James, thereafter by all the apostles. Yet, last of all, even as if a premature birth, He was seen by me also." (1 Corinthians 15:1-8)
The evangel (gospel) that Paul "accepted" as I understand it:
"Christ died for our sins according to Scripture". For 3 days and nights He was dead, without life and no longer aware of His surroundings (no longer a living soul).
"He was entombed" for 3 days and nights. His soul did not sleep, the soul does not sleep, it ceases to do its job of making one aware of being alive.'
"He has been roused the third day according to the Scripture". The spirit of God returned to His body and He became once again a living soul, aware of His surroundings.
"He was seen by Cephas (Peter), thereupon by the twelve. Thereupon He was seen by over five hundred brethren...by James, thereafter all the apostles. yet last of all...He was seen by me (Paul) also". Tthe disciples of Jesus, His brother James, and the apostle Paul did not believe the gospel until they had actually "SEEN" Jesus after He was resurrected.
So, it is truly a miracle for us, 2000 years later, to believe the gospel when none of us has SEEN the risen Lord yet. We can only "accept" it in faith.
That the closest friends and apostles did not believe the gospel until they had "seen" Jesus after His resurrection helps me in times when I fight the temptation to question the truth of the gospel (I may be the only Christian who does, but I am being honest).
I'm more like the father who said to Jesus with tears "I am believing! Help my unbelief!" (Mark 9:24)