The Law was never intended to save. It was given to people who had from birth transgressed it and, therefore, could not be perfect—as it demanded. Of course, God knew this when He temporarily set it up to demonstrate human sin and lostness, and (therefore) the vital need for a Savior. The cross is central to our faith.
Jesus was able to keep the law, since from birth, He was sinless and capable of doing so, and also could, therefore, die for lost sinners who had not kept it. Judaizers want to throw in the keeping of the commandments by sinners as a part of salvation which intention, as can be readily seen, is preposterous.
But there are some who think that instead of dying on the cross to justify us in God’s sight, which is what the Lord did for us, Jesus also kept it to sanctify us, and that this process of sanctification is now going on as a result of our focusing on the cross.
No one would deny that to focus on the cross from time to time is a good thing to do. But, that isn’t the way to become sanctified. This view has Jesus keeping His own commandments to sanctify us. But sanctification has to do with believers becoming more like Christ by “observing (obeying) whatsoever He has commanded” them (Mt 28:30). They, themselves, must obey; He does not do for us, instead of us, what He has commanded us to do. Indeed, observing His commandments is what the church ought to be “teaching” its members to do rather than mystically contemplating the death of Jesus. To teach this latter, new doctrine, is to boarder on Medieval mysticism. To teach this as the task of the believer, rather than to “observe” Christ’s “commandments” by the wisdom and power of the Spirit, is placing Christians on a pathway that leads back to Rome.