βFor which cause we faint not; but though our outward man perish, yet the inward man is renewed day by dayβ (2 Cor. 4:16).
Romans 12:1-2 tells us: βI beseech you therefore, brethren, by the mercies of God, that ye present your bodies a living sacrifice, holy, acceptable unto God, which is your reasonable service. And be not conformed to this world: but be ye transformed by the renewing of your mind, that ye may prove what is that good, and acceptable, and perfect, will of God.β
Ephesians 4:20-23 says: βBut ye have not so learned Christ; If so be that ye have heard him, and have been taught by him, as the truth is in Jesus: That ye put off concerning the former conversation the old man, which is corrupt according to the deceitful lusts; And be renewed in the spirit of your mind; And that ye put on the new man, which after God is created in righteousness and true holiness.β
The key to Christian living is letting Jesus Christ teach you how He wants to live His life in and through you. It is not something you struggle to do, but something you daily learn from His Word rightly divided (2 Tim. 2:15). Faith causes the Holy Spirit to take that Word and change your thinking processes, and that will change your conduct to fit Godβs grace. Colossians 3:10 adds: βAnd [ye] have put on the new man, which is renewed in knowledge after the image of him that created himβ¦.β We are building up the inner man, preparing for the day when God relocates it to the new outward manβ¦.
βFor we know that if our earthly house of this tabernacle were dissolved, we have a building of God, an house not made with hands, eternal in the heavensβ (2 Cor. 5:1). source