He alone justifies believers. This principle also applies to sanctification. He alone makes us holy. God is the cause and content of our sanctification. Traditional Roman Catholicism shares with Lutheranism a monergistic view of the general plan of salvation.
Sanctification requires cooperating with divine grace in doing good works.
At the center of this system is a doctrine of sanctification which holds that man cooperates with God for the certainty of salvation. There is no place for the total justification of sinful humanity as God's completed activity in Christ. Man cooperates with God in becoming holy and so sanctification is defined in ethical terms, which can be measured. A majority of other Protestant denominations agree with Luther's monergistic doctrine of justification, but like Roman Catholics they see sanctification, the working of the Holy Spirit in Christian lives, in synergistic terms, another Greek derivative, which means that a thing has two or more causes. Believers are required to play a part in developing their personal holiness by living lives disciplined by the Law and by special ethical regulations set down by the church.