It has been a concern throughout history that the belief in justification by faith alone leads to a sort of moral laziness. It has been argued that because one is saved by faith alone independent of our moral actions, people would become lazy in doing what is right given the fact that salvation is not based upon what we “do”. Indeed, the Apostle Paul asked this very question. Consider Romans 5:20-21 when Paul says, “Now the law came in to increase the trespass, but where sin increased, grace abounded all the more, so that, as sin reigned in death, grace also might reign through righteousness leading to eternal life through Jesus Christ our Lord”. With the increase of sin, the grace of God abounded all the more. However, the Apostle Paul did not believe that therefore one should continue in sin so as to allow God’s grace to shine forth even more so. Indeed, Paul asks the very question: “What shall we say then? Are we to continue in sin that grace may abound? By no means” (Romans 6:2).
The Apostle Paul expands on his reasons for not allowing God’s grace to become an excuse for more sinning. Indeed, because we have died with Christ and have been raised with him, we are set free from the power of sin and death. In essence, we are resurrected persons who experience a new life and identity in the Person of Christ himself. Hence, in light of this fact, why should we continue to walk in the ways of our old self, which was enslaved by sin; to do so would be inconsistent with this new calling that we currently, as saved individuals walk in.
It is also very important to understand what justification is in order to adequately address the question of whether it leads to moral laziness or laxity. Justification is a declaration of righteousness resulting from faith in the Person of Jesus Christ and his cross work. This declaration refers to our position in Christ as righteous and innocent before the Father because of the work of Christ. There is no connection per-say between justification and ethical behavior. One is not justified because of ethical behavior, rather one is justified by faith, which is itself a gift of God (Eph. 2:8, Phil 1:29). When a person is “justified”, he is declared righteous; he is not intrinsically made righteous such that the person now does not nor cannot sin. The movement from sinning regularly to a person who sins less is related to the process of sanctification whereby the Spirit of God, through the course of our lives molds us and transforms us more and more into the image of Christ. It is in the sanctification process where we see the moral growth of the saved individual move towards a more Christ-like conduct.
With having said this, the doctrine of justification by faith alone will not lead to moral laziness or laxity because the one who is justified (declared righteous before God), is then indwelled with the Spirit of God who convicts, teaches, and corrects us as he leads us to be more Christ-like. It is important however, to keep in mind, that God works differently in different people. That is to say, that the sanctification process whereby we are molded more and more into the image of Christ may manifest itself more evidently and rapidly in some, and more slowly in others. But, if a person truly is in Christ, and is desiring to please God out of a genuine love for him, such a person will not willingly be lazy or lax in doing good; but even if the person does for a time, eventually, if the Spirit indeed indwells such a person, the person will eventually desire to move from such laziness to a life that is more intentional about pleasing God; “for it is God who works in you to will and to act in order to fulfill his good purpose” (Philippians 2:13).