God does not believe for us, but through His Spirit He creates spiritual life in us so that we can believe. Faith is the gift of God. It's part of the whole salvation package that God gives to us through the work of Christ for us and the work of the Holy Spirit in us. It's not our contribution, so to speak, to God's great plan of salvation. God does it all. It's part of the unsearchable riches of Christ.
Jerry Bridges