1Now faith is the assurance of things hoped for, the conviction of things not seen.
2For by it the men of old gained approval.
3By faith we understand that the worlds were prepared by the word of God, so that what is seen was not made out of things which are visible.
Hebrews 11:1-3 (NASB)
Faith is simply taking God at HIS Word.
It's believing that the Bible is the Word of God.
And my God will supply all your needs according to His riches in glory in Christ Jesus.
Philippians 4:19 (NASB)