In the scripture, one believes because God chose them to believe. He first Loved them from everlasting, chose them in Christ, Christ came in time and put away their sins, and in time the Spirit comes to the blood washed sinner, gives them Spiritual life, sets them apart unto belief of the Truth. 2 Thess 2:13I am glad I chose to believe so God would "shine the light of the glory of God in the face of Jesus Christ" to me. (2 Cor 4:6)
From the beginning, God knew that it would take belief of the truth and sanctification of the Spirit for me to be saved.
Are we on earth able to distinguish the "chosen" from the "unchosen"?
13 But we are bound to give thanks alway to God for you, brethren beloved of the Lord, because God hath from the beginning chosen you to salvation through sanctification of the Spirit and belief of the truth:
Paul thanks God for their belief of the Truth, not the sinner. Paul knew it was God that caused their belief of the Truth. Whereas in your beliefs you as you just said, its you who made the decision to believe, and then your god responded to you.