Matthew 5:17 Do not think that I have come to destroy the Law or the Prophets. I have not come to destroy but to fulfill.
When Jesus said that he came to fulfill the law, he meant that he would make it so we wouldn’t have to keep the law ourselves.
Romans 13:8-10 Owe no one anything, except to love one another; for he who loves another has fulfilled the Law. (9) For: “Do not commit adultery; do not murder; do not steal; do not bear false witness; do not lust;” and if there is any other commandment, it is summed up in this word, “You shall love your neighbor as yourself.” (10) Love works no ill to its neighbor, therefore love is the fulfilling of the Law.
Galatians 5:13-14 For, brothers, you were called to liberty. Only do not use the liberty for an opening to the flesh, but by love serve one another. (14) For all the Law is fulfilled in one word, even in this, “You shall love your neighbor as yourself.”
James 2:8 If you fulfill the royal Law according to the Scripture, “You shall love your neighbor as yourself,” you do well.
When Paul and James said that we fulfill the law by loving one another, they meant we only need to love one another once because then the law will be fulfilled and we won’t need to keep it anymore. But they were really just wasting ink since Jesus already fulfilled the law once for everyone. We don’t have to love anyone even once now because that would be trying to keep the law and that’s legalism.