Rose

On the third day he rose again in fulfillment of the Scriptures; 

Nicene-Constantinople Creed

This is the thing, this is the reality the first generation, the eye-witness generation was at great pains to tell us.   This is the miraculous thing.

Resurrection of the dead was not an unknown concept in the first century. We can see from the New Testament that it was a hot debate among Jews with the Pharisees (like Paul!) firmly holding that the dead would rise and the Sadducee's arguing against.

Is it any wonder Paul was ready to believe in Resurrection when he heard the voice of Jesus on his way to Damascus?  He would later write "he is the beginning and the firstborn from among the dead." Colossions 1:18

Luke claimed to have heard it from others but her wrote about events "just as those who were eyewitnesses from the beginning and ministers of the word have handed them down to us..." ( Luke 1:2: )

Was the author of 2Peter the apostle Peter? Scholars suggest not. Whoever wrote it wrote as if he too were an eyewitness, "We did not follow cleverly devised tales when we made known to you the power and coming of our Lord Jesus Christ, but we were eyewitnesses of His majesty." (2Peter 1:16)

And again Paul wrote "After that, he appeared to more than five hundred brothers at once, most of whom are still living, though some have fallen asleep." (1Corinthians 15:6)

We have no such access to eyewitnesses. "We walk by faith and not by sight." (2Corinthians 5:7) That's as it should be; the saints walk with us. Is it not logical that he would go back to His Father?