Jesus was asked, which of the laws were most important. He replied, ' To love the Lord your God with all your heart, soul and mind, and to love your neighbor as yourself.
Apart from laws having to do with clothing, ceremonial washings and food consumption, which, under grace, are no longer applicable, I sincerely believe that if we obey these 2 laws, it is impossible to break any other law. If we genuinely love the Lord our God, we will do nothing to grieve his Holy Spirit, and if we love our neighbors as ourselves, we will do nothing to harm another person. I believe this is the reason Jesus answered in this way.
The law will not, and has not, perished. But, it certainly serves a different purpose in our day. Galations 3:10 says, all who rely on observing the law are under a curse. Gal. 3:12 says, the law has nothing to do with faith. I Timothy 1:9 says , the law is not made for the righteous, but for the ungodly, the rebels and the sinful.
These things were written so that, though the righteous believe and obey through faith, , there would remain a standard which condemns the wicked. It is the standard which continually points the way to the cross and to the call for repentance. It is a standard which stands as a witness against all ungodliness so that the wicked are without excuse, because sin has been thoroughly and clearly defined. But the law is no longer our teacher, the Holy Spirit has filled that place in the lives of believers. The law is no longer our salvation, because no man will ever again be considered righteous by simply obeying the law.
Legalistic teachings will continue to encourage, with great persuasiveness, that we are to live, dress and generally abide by the law, but this is a teaching that fails to see the law for what it is, the standard which calls for repentance and points the way to Jesus. It is not by the works of the law that we are saved, lest anyone would boast of his ability to obey the commandments, but through faith alone.