Most scholars of ancient works agree Jesus did exist as claimed in the Bible. Jesus is mentioned by the Jewish historian Josephus, who lived contemporarily with the apostle John, and the Roman historian Tacitus. Then came many more historical mentions and large works in the next century and continuing. Jews never wrote denying Jesus existed, but made it clear they didn't believe his link to divinity. They still look for the Messiah, who will meet the demands of their scholars. That's in spite of the huge statistically significant fact of Jesus' fulfillment of many prophecies from Jewish prophets. They just can't accept Christian claims about him. Now, if a person wants to diminish the reliability of authenticity of ancient writings because they were authored after a subject's death, then secular works such as Socrates, Plato, Aristotle should also be suspected, seeing the oldest manuscripts belong to a period 1,200 years after Plato died. Any Christian challenging the authenticity of Plato's words is subject to derisive abuse. As for why Jesus stayed around 40 days after his resurrection, he actually reported to the Father God right away, then returned later that day to visit the apostles. By staying with them that period he was ale to complete their understanding about what had happened. That experience helped them come out of hiding, then assemble publicly until Pentecost in the midst of the hostile Jews for 10 days after Jesus ascended for the last time.. He won't ever ascend again, but will descend and remain for a thousand years according to the Bible. Let me suggest that shopping religions ought not be similar to looking for just the right feeling like searching for that just right lounge chair. The world has invented many religions before and after Christ in attempts to define and deal with divinity and the supernatural, unlike the animal kingdom. Christianity is not like world religions, not given to be adapted to the ever changing comfort level of people around the world. It's the only faith with God giving his eternal son to die for our benefit. Typically other religious man-made gods are too selfish to do such a thing, in particular to love underachieving people. Christianity is given for the changing of individuals one by one mostly, who then influence their communities to change the way God desires, while world religions tend to affect groups of people directly, like Hinduism affecting all of India, which in turn regulates the individual. They lack individual relationship with any god until embracing Christianity, which millions are doing today. Technically you can't discover Christ by your own effort, but can only encounter him when the Father God decides. None can meet him except by way of the Father. Like the parables taught, invitations to come to a banquet were not continually sent out to the same people over and over, but were offered to a majority of least likely candidates. It's wise to not delay too long in accepting your invitation from God. That's my prayer for you.