Purity often involves a process. The twofold purification process in the believer's life commences at the moment of salvation. This process then progresses as the believer walks with the Lord. The individual's faith in the finished work of Christ washes away one's sin in Christ’s blood. Christ's blood cleanses completely and purifies every believer from his sin. This cleansing and purification remains forever settled between the Lord and the believer. The born-again Christian will never and can never again be any less pure in his position with the Lord. Peter confirms the positional purity when he wrote that his audience had “purified” (past tense) their souls (1 Peter 1:22). Our purity in position, settled by trusting Christ as Saviour (Titus 2:14), cannot be reversed. However, positional purity does not guarantee purity on a daily basis during our walk. The Christian's practice (his walk) must by choice remain pure.
Christians should first and foremost focus on their walk with the Lord. As such, believers are instructed to add virtue, knowledge, temperance, patience, godliness, brotherly kindness, and charity to their faith. However, notice that every believer is to be “giving all diligence” (with great effort, but without haste). Of all these graces mentioned, faith seems to be the most foundational of them all. Unfortunately, far too many believers never grow beyond faith, making them unable to put forth much diligence in adding the other graces. Believers should be growing in grace daily (like those listed above) and in the knowledge of our Lord and Saviour (2 Peter 3:18). The word of God remains the only viable source from whence this diligent growth springs forth (1 Peter 2:2).
