God's note is the Bible. It says, "You will receive power when the Holy Spirit comes upon you...I will give you a new heart...Old thing pass away, all things become new."

I believe the Bible, not because I welled up some sort of faith in its words, but because it said that God would make me a completely new person if I would repent and trust alone in Jesus.

It authenticated itself as the Word of God by supernaturally doing what it said it would do. The power came on and transformed me overnight into a brand new person.

This didn't come about because of anything I did. It was a completely independent source of power that took me out of darkness and brought me into light. Therefore every other promise in it about Heaven, Hell, and everlasting life is utterly true altogether.