Increasing our desire for soul winning begins with understanding that God values every person and desires none to perish. Our role is not to convince or convert others but to faithfully witness and make disciples, leaving the work of drawing hearts to God Himself. True desire for soul winning grows as we recognize humanity’s desperate need for salvation, the certainty of judgment without Christ, and God’s unique provision of salvation through Jesus alone. God empowers and sustains our witness. His Holy Spirit works in us to reflect and share Him to the world, and He also convicts the world of sin, drawing hearers to Himself. Our call is to be faithful to witness and share the gospel; God will do the rest.
Knowing we are called to witness and reflect who God is, and that God will draw people to Himself, how can we increase our desire for soul winning? The only way to increase our desire for soul winning permanently is to ask God to increase our desire to witness. It's not something we can work up for ourselves; we must walk at the direction of the Holy Spirit, asking God to lead us. We can witness in our own strength, but that lasts only a while. Reading the Bible and understanding man's hopelessness and ultimate destination without Jesus does help. Romans 3:23 says that all men have sinned and fall short of the glory of God. Then Romans 6:23 states that "the wages of sin is death." These two verses taken together make it clear that all men in and of themselves are doomed. We can ask God to make this truth real to us and to give us His love for all men. The assurance that, without Jesus, mankind is doomed and a real love for people will lead us to want to tell them of the only way they can be saved from sure destruction, which is through Jesus. Acts 4:12 says, "And there is salvation in no one else, for there is no other name under heaven given among men by which we must be saved." It is also helpful to think about the ways God works in our own lives. The more we know God and experience life in Him, the more we will want to share that life with others. Steeping ourselves in God's truth will help transform our minds and align our hearts with His.
God is the one who draws men to Him for salvation. He is the One who wins souls. We can ask Him to create in us the desire to witness and the courage to do so. He will take care of the rest.