Unconfessed sin will make a Christian doubt their salvation and security in Jesus Christ. It is most important in times like this that they look to Scripture for the promises of God. Paul explains in this sermon on Romans 5:10 that God’s children are eternally safe and secure in Christ Jesus because of the work that He did on the cross. In the sermon titled “Security in Christ,” Dr. Martyn Lloyd-Jones discusses this assurance by focusing on this one verse in Romans. First, God sacrificed His Son on the cross to be the propitiation for sin. That act removed the enmity between God and saved humanity who were previously enemies with God. God chose not to impute their trespasses on them. Instead, He imputed the trespasses on Himself and imputed to His people His righteousness. If God did such an act as this to show His love, how much more would He continue that good work in His people? This new relationship with Christ means that His people are grafted into Christ and nothing can change that status.

http://www.mljtrust.org/sermons/security-in-christ/