What then must we do, in order to live according to the will of God?

Whoever desires to love and obey God must, as the Lord teaches, “deny himself” (Mrk 8:34). This denial of the flesh and of “the power of sin” is not loss, but gain, “victory through our Lord Jesus Christ” (1Co 15:56–57; see Q043).

As St Basil the Great explains:

Whoever denies himself puts off the old man with his deeds, which is corrupt according to deceitful lusts (Col 3:9; Eph 4:22), and renounces all worldly attachments that can hinder his intention of godliness. Perfect self-denial consists in this: that one cease to have affection even for life itself, bearing the sentence of death in himself, that he may not trust in himself… before all else we renounce the devil and the cravings of the flesh… and any manner of life at war with the strict way of the Gospel of salvation… and such a one will deem as his true parents those who begot him in Christ Jesus through the Gospel (1Co 4:15), and as his brothers, those who have received the same Spirit of adoption (Rom 8:15). (St Basil the Great, Great Asketikon [Long Rules 8]).

This new way of life is the gift and fruit of the Holy Spirit, through whom believers see things as they truly are and obtain the freedom of the Spirit (2Co 3:17; see Q107, Q162). As St Innocent writes:

The Holy Spirit corrects a worldly outlook and attitude, so that the Christian is no longer overwhelmed by the temptations of this passing world. Gratefully using what God has bestowed, a true Christian is not attached to anything temporal, but considers himself a stranger in this world, and wishes above all to be in communion with God. (St Innocent of Moscow, Indication of the Way into the Kingdom of Heaven)