Billy Graham stated, "The will is necessarily involved in conversion. People can pass through mental conflicts and emotional crises without being converted. Not until they exercise their prerogative of a free moral agent and will to be converted are they actually converted" (Billy Graham, World Aflame, Minneapolis: BGEA, 1967) p.134. Scripture teaches likewise that the will of man is involved in conversion. "Today if you will hear His voice harden not your hearts" (Hebrews 3:15). The obvious point is stated clearly. An unwillingness to hear God's truth leads to a hardened heart. God gives us a choice.
Man left to himself in his sinful state will never desire nor will to be converted. "There is none who understands. There is none who seeks after God" (Romans 3:10). God initiates a relationship with us. He calls us by His grace. The Holy Spirit convicts or convinces us of sin, judgment and righteousness (John 16:7-11). If that does not happen, then there is no conversion.
Grace precedes our conversion. This preceding grace prepares the heart to receive the good news of Christ. Until that happens, man in his sin has no desire for God nor to hear the word of God. A woman by the name of Lydia heard the apostle Paul preaching the gospel. "The Lord opened her heart to heed the things spoken by Paul" (Acts 16:14). That is preceding grace which comes before conversion.
God never forces the will of man to be converted. He works through the will. No violence is ever done to the will. Jesus said, "Behold, I stand at the door and knock. If anyone hears my voice and opens the door, I will come in to him and dine with him, and he with Me" (Revelation 3:20). The sequence to conversion is plain for all to see. He initiates the relationship. He speaks and knocks at the door. Nevertheless, we must open the door. Conversion is a choice.