@Radical_EgoCom An excellent question! Depending on where one's doubts of Jesus's words lie, I might answer different points. But, a few brief thoughts:
1.) the amount of testimony of Jesus's miracles, death and resurrection is quite high (relatively speaking in the ancient world). While many people claim divinity, there aren't usually records of _many_ of the surrounding circumstances. Often if miracles are attributed to a figure, we find they weren't attributed by first hand witnesses.
2.) those who witnessed these things, believed them, confessed them and were willing to die for them. (Not just those who later on were told them, but the ones who knew if they were following a lie or not, because their own eyes saw whatever they saw or didn't see.)
3.) There was little or no benefit to believing and confessing these things if they knew them to be untrue.
4.) A Christian also believes God's Spirit testifies about His Word, and to me, I believe that experiential aspect is the most profound, though it obviously can't prove anything to someone else. It would be God showing you or anyone else that.
I realize none of this gives a complete reason. But hopefully it is at least helpful in understanding the mind of someone who does believe.