How do we know that believers are pure?

Believers can be assured of their purity through the transformative work of Christ. In John 13:10, Jesus tells Peter, 'He that is washed needeth not save to wash his feet, but is clean every whit.' This indicates that those who are washed by Christ’s sacrifice are made pure inside and out. Furthermore, 1 John 3:9 declares that 'Whosoever is born of God doth not commit sin,' meaning that the new nature given to believers does not sin. Every believer possesses this new heart, establishing their identity as pure through the righteousness of Christ and the cleansing power of His blood.