Is assurance essential for salvation? Can one doubt their salvation and still be truly saved? In this sermon on Romans 8:15 titled “The Spirit of Adoption,” Dr. Martyn Lloyd-Jones answers that assurance is not essential for salvation. It is possible for those who have truly been born again and who trust in the Gospel to doubt if they have been saved. This is because they are saved by the work of Christ, not our act of believing. It is not as if faith is a great work that earns the Christian favor with God. Scripture tells that faith itself is a gift from God in order that the Christian might be saved. Salvation is received by God enabling them to believe in the gospel. This is a great hope to all who are plagued by doubts of God’s love for them. Salvation is a gift of God, but not all who are saved are assured of their salvation. As Christians grow in love of God and neighbor and to understand God more and more, all Christians can have a stronger assurance of salvation. All believers can know that Christ has died for them and loves them.

http://www.mljtrust.org/sermons/the-spirit-of-adoption/