John 6:43-45 (NASB) 43 Jesus answered and said to them, "Do not grumble among yourselves. 44 "No one can come to Me, unless the Father who sent Me draws him; and I will raise him up on the last day. 45 "It is written in the prophets, 'And they shall all be taught of God.' Everyone who has heard and learned from the Father, comes to Me.

Romans 10:17 (NASB) So faith comes from hearing, and hearing by the word of Christ.