How does faith come?

Since “faith” is a broadly used term, it is important to understand that we must start with a general faith in God, as opposed to a specific type of faith, such as “saving faith”, or :”healing faith.” Faith (or belief) is not in something or someone unknown, or unknowable. So the first step in faith formation has to be “hearing.” Hebrews 11:6 (God’s Word Translation) reads, “Whoever goes to God must believe that God exists…” Such belief cannot exist unless one is told about who they should believe in; namely, the Creator God of Genesis. Such direction can come from a natural source (a preacher, evangelist or fellow believer), or supernatural source (the Holy Spirit Himself), but unless one “hears” of the One in whom they should have faith (belief), their faith is shallow, at best, and hollow, at worst. Stephen notes, in his pre-martyr sermon, that God appeared to Abram giving him direction for his faith (Acts 7:2), which is confirmed by Moses, as he writes that “The Lord had said to Abram… (Genesis 12:1, NIV, italics mine).” This was a supernatural word spoken and heard by the father of the Israelites, which initiated his faith. God’s commitment to make Abram into a great nation and to bless “all peoples on earth through” him (Genesis 12:3, NIV) confirmed the word heard.
After the word is heard, there will be opportunity to act on it. God allowed Abram to act on his faith by following the command to go (Hebrews 11:8), and, later, by offering his son Isaac as sacrifice (Hebrews 11:17), and having God credit his faith (belief) as righteousness (Romans 4:3). That activity continues throughout a lifetime, with God delivering on his promise without fail in every instance, thus ensuring that the next step is insured: relationship. Faith grows as God shows Himself faithful. He is, after all, unable to do or be anything less (Hebrews 10;23).