2 Corinthians 7:1 “Therefore, having these promises, beloved, let us cleanse ourselves from all filthiness of the flesh and spirit, perfecting holiness in the fear of God.
Our sanctification must be built on gospel promises, in reverent obedience to God. The only way we will progress in this sanctification, overcoming the sins of the flesh (those committed with the body) and the spirit (those committed in the heart and mind), is by standing on the promises of God and walking in the fear of God. Note how the apostle Paul emphasizes this truth earlier on in 2 Corinthians:
For the Son of God, Jesus Christ, who was preached among you by us-by me, Silvanus, and Timothy–was not Yes and No, but in Him was Yes. For all the promises of God in Him are Yes, and in Him Amen, to the glory of God through us. Now He who establishes us with you in Christ and has anointed us is God, who also has sealed us and given us the Spirit in our hearts as a guarantee. (vv. 19-22)
As a side note, notice that Paul speaks of God, Christ, and the Spirit as playing a part in this. Just as much as the gospel is Trinitarian (Eph. 1:3-14), so too our progress in sanctification is Trinitarian. This only makes sense, for if our pursuit of holiness is grounded in and built on the gospel, and the gospel itself is Trinitarian, then our sanctification too must be Trinitarian.
Further, the fear of God is essential to our pursuit of holiness (Prov. 2:1-9). The person who fears not God, fears not sin and its consequences. “The fear of the LORD is to hate evil….” (Prov. 8:13a). The person who fears not God, fears not that all our sins are fully known and seen by Him to whom we must give an account (Heb. 4:13). Let us walk in the fear of the Lord then, knowing that we have been redeemed with the precious blood of Jesus Christ (1 Pet. 1:17-19).