Atheists answer please: Why do you need so much evidence to believe something exists?

I'm not trash talking you at all, just trying to understand an atheists logic on their belief system. I have an atheist friend, not saying all of you think the same...But we were discussing the resurrection of Jesus and he said, "I'm not saying it didn't happen, but since there is no evidence, he can't believe it himself" I Just want to know why you need so much evidence to believe something happened or is not real. Why can't you believe that Jesus died, then was resurrected. None of us was there to see it, yet I go with my heart and faith and believe. Something big started Christianity and I believe it was the resurrection 100%. I don't need to be there to believe something, that includes UFO's, ghosts, etc. Sometimes you just have to go with your heart right? Why can't you?