The relationship between justification, union with Christ and sanctification.

From the reformed perspective the relationship between justification, union with Christ and sanctification is more simultaneous than linearly represented on a timeline. Justification is God’s declarative act, external from the believer to acquit their sin and impute Christ’s righteousness upon them by covenanting with the believer and entering into a relationship that promises life. That relationship is best seen as union with Christ, which literally gives the believer life. This is not an ordinary life, but one that is transformative of the mind and a renewal of the will to seek and worship God above anything else. Union with Christ offers the believer an everlasting hope and a secured promise of eternally life based on the justifying act of God’s declarative righteousness. At the same time that righteousness and everlasting life are offered to the believer, so they are changed, purified and made holy by the sanctifying power of the Holy Spirit. Jesus Christ chooses to tabernacle within the heart and mind of the believer, changing them forever from sin to righteousness as he becomes sin for us. Justification, union with Christ and sanctification all come to us instantly the moment the believer is saved. Each will be fully realized upon the resurrection and glorification of the body, but each are also fully promised and granted to the believer in the salvific gift of God’s grace.