You know it is true they saw Jesus alive from the dead because people don't willingly die for something they know is a lie and they were martyred for this claim. Since you can't find a naturalistic explanation to account for this, realize Jesus is God for only God can resurrect. The Christian account is not dying for some idea but for their eyewitness testimony. The New Testament provides a full account of their testimony. Think of atheism as a cult, how they try to manipulate you all the time flipping back and forth from a universe that always existed to it popping into existence all by itself. We know our universe is only 13.7 billion years old and we know the exponential progression of conscience disproves an eternity of the past of cause and effects. Thus we are left with only one possibility, the uncreated Creator created. This is whom we call God.

Study the multiple attestation by the Apostles. Time to put your thinking cap on and stop arguing for argument-sake,

http://www3.telus.net/trbrooks/12groups.htm

If you have an honest heart you will come to realize that since Jesus was not a liar nor a lunatic, there is only one possibility, He must be God who said He was co-equal with the Father in the Trinity.