“We don’t believe something by merely saying we believe it,” he said, “or even when we believe that we believe it. We believe something when we act as if it were true.” — Dallas Willard
Not sure you whether or not you believe in God, not confident that you have faith in Jesus, act as if you do. Act as if you do and give the Holy Spirit time to work on and in you.
Dallas Willard, cited by Rachel Held Evans, Inspired: Slaying Giants, Walking on Water, and Loving the Bible Again (Nashville, Tennesee: Thomas Nelson, 2018), 186.