I like to broaden my knowledge through your capabilities..., here is a couple of things why i believe Christianity is wrong..Mind you, im looking this through an Atheist viewpoint.
After Jesus made the above mentioned prayer he was answered by God according to Hebrews 5:7 " Who in the days of his flesh, when he had offered up prayers and supplications with strong crying and tears unto him that was able to save him from death, and was heard in that he feared". These words clearly show that when Jesus was praying strongly to God, God would grant him his request. The word " heard in that he feared" (Hebrews 5:7) mean that God granted him what he requested. So the above verse shows that when Jesus asked of God to " let this cup pass from" (Matthew 26:39) him, God respond to his prayer and saved him from death or crucifixion.
In general, this is a bit size amount of my arguments, i shall post more if i get some good insights...I wish i could get refuted, as i would like to give justice to this major religion. If this is not the right place to post my questions/arguments please let me know!