“Since you have purified your souls in obeying the truth through the Spirit in sincere love of the brethren, love one another fervently with a pure heart.”
through the Spirit (not in some manuscripts)
The Holy Spirit is the agent who purifies our soul. The Spirit motivates us and makes us effective in living the Christian life. True Christian living is produced by the Spirit. The Spirit produces true love (Gal. 5:5; 22; Ro. 5:5; Heb 9:14).
Both divine and human factors are important in the Christian life. The Christian life has two handles. God provides the power to live the Christian life giving us confidence by the Spirit. We produce action living out of God’s power. Man’s part is to co-operate with God’s power.
The agent of purification is the Holy Spirit.
The new life in Christ is not of ourselves but through the Holy Spirit. The word “Spirit” means breath or wind. Unless we set our sails the wind will pass the boat and leave it motionless. Unless believers allow themselves to be filled with the Spirit, we will be powerless to live the Christian life.
The agent of purification is the Holy Spirit. The moment people receive Jesus Christ as their Savior the Holy Spirit comes to lodge in their lives. We can quench the Holy Spirit (1 Thes. 5:19) or grieve him (Eph. 4:30) by sin.
The supernatural life in Christ has supernatural effects. If a person is truly born again there will be a fruit of supernatural nature especially the kind of fruit produced in this verse.