Faith comes by hearing the Word of God spoken to you from God in your day. It is the revelation of Jesus Christ that imparts that faith, because Jesus Christ is the Word, and that is the one to hear in order of have saving faith.
Matthew 17:5 KJV
While he yet spake, behold, a bright cloud overshadowed them: and behold a voice out of the cloud, which said, This is my beloved Son, in whom I am well pleased; hear ye him.
He is the Word of God, therefore hear ye him! That is the only way faith comes. Abraham heard him and faith sprung up in him: Isaac, Jacob, Joseph likewise heard him, and faith immediately gushed out.
Moses, Joshua, David and the prophets heard him and they received that faith. The apostles heard him speak and believed by which they received that faith.
What of you? Have heard him today? For there no other way to have faith but by hearing him who is the Word of God.
Romans 10:14-17 KJV
How then shall they call on him in whom they have not believed? and how shall they believe in him of whom they have not heard? and how shall they hear without a preacher? [15] And how shall they preach, except they be sent? as it is written, How beautiful are the feet of them that preach the gospel of peace, and bring glad tidings of good things! [16] But they have not all obeyed the gospel. For Esaias saith, Lord, who hath believed our report? [17] So then faith cometh by hearing, and hearing by the word of God.
So was Caleb's faith built; upon this rock, this firm foundation, he did built his faith by which he overcame the world, and tests in glory.