True faith is an act of the will, in the sense that God gives us a new will in the new birth, along with faith (John 1:12-13; Ephesians 2:8). God does not make us robots; he successfully woos our hearts. Faith is not merely an act of the will, because it is also the act of the Holy Spirit in our souls, drawing us to Jesus Christ, and bringing us to trust in him as he is revealed in his Word (James 1:18).
This is fundamentally different than 1) the “easy believism” which says that if you ever signed a card or mimicked a prayer then you are saved no matter how you live afterward, and 2) the “name it and claim it” health-and-wealth promises that faith somehow manufactures blessings. Faith believes in something that is true; it does not make something true and then believe it.
Faith believes in something that is true; it does not make something true and then believe it.
You have trusted in Jesus’ work on the cross alone for your salvation. You asked to be changed and trusted that God would do it. Although you have not been made completely perfect yet, have you not seen God working in your life? Causing you to hate the very sins that you have committed, causing you to desire to be sinless, and causing you to come back to Jesus again and again in repentance and faith? If so, this is certainly a good sign that your faith is genuine.
True faith is by grace alone, in Christ alone; it is a conscious choice (an act of the will) to respond to the glory of God, in Christ, as revealed in his Word. And it perseveres through the ups and downs of life because God is continuing in you the same work he began in you (Philippians 1:6).