Are you attempting to keep the law of God or living in His strength and grace?
Think not that I am come to destroy the law, or the prophets: I am not come to destroy, but to fulfil. For verily I say unto you, Till heaven and earth pass, one jot or one tittle shall in no wise pass from the law, till all be fulfilled. Whosoever therefore shall break one of these least commandments, and shall teach men so, he shall be called the least in the kingdom of heaven: but whosoever shall do and teach them, the same shall be called great in the kingdom of heaven. (Matthew 5:17-19 KJV)
This was a teachable moment and Jesus is speaking to His disciples away from the throngs of the crowd upon a mountain top. These verses are a small portion of the Sermon on the Mount which was a powerful collection of precepts Jesus spoke to His inner circle of disciples who were familiar with the many Mosaic laws of the Old Testament.
There was and is much confusion about the law of the Old Testament and the present New Testament age. Jesus was explaining to His disciples that He came to fulfill the law; not destroy it. Jesus Christ did not make the law extinct and void and without meaning; but rather to fulfill it or bring it to its end; completing it or achieving the desired finish. Jesus Christ perfectly fulfills the law.
In the Old Testament the law was like a mirror showing people who they were and how they stacked up against the measure of the law. There were over six hundred laws and no man could keep them. Keeping the law would require perfection and mankind was born naturally imperfect complete with a naturally raging sin nature that operates against or in opposition to keeping the law.
But Jesus Christ is perfectly sinless and righteous. He is the only one who could bring about the Old Testament Mosaic law to completion through His shed blood on the cross at Calvary bringing about His holiness and perfection as a free gift for mankind. Mankind could never hope to accomplish such a monumental task being filled with a sinful nature from birth; failing greatly in his own strength or attempts to keep the law.
Are you trying to live by the standards of the law like the Pharisees failing in your own attempts and strength? Or are you living through the holiness and perfection of Christ who accomplished the law and now works in us and through us who are His unto perfection in the eternal realm?