This is what I believe and I catch flack from both sides, Calvinists and non-Calvinists , but so be it!
The faith is in the message of the Gospel.
Remember Paul said, faith comes by hearing and hearing by the Word of God.
When a person hears the Gospel that Paul preached and shame on our preachers who don't preach that same Gospel, the Holy Spirit works from that hearing making the truth of the Gospel real in the heart.
If man accepts that Gospel then the Holy Spirit provides with that conviction the faith needed to believe unto eternal life.
Paul said that, "from the heart man believes unto righteousness."
The heart is convicted, the heart believes, and righteousness is imputed through that faith.
@unprofitable
Paul explains all of this in Romans 10.
Romans is called the heart of the Bible. It's where Paul explains exactly what we must do to be saved, where the faith to believe comes from, why some will not be saved, the entire time using Israel as the example.