Does Paul's teaching contradict Matthew 5:17-20?
Romans 6:14
"For sin shall no longer be your master, because you are not under the law, but under grace."
The law has no glory at all in comparison with the New Covenant. (2 Corinthians 3:10)
Christians are dead to the law. (Galatians 2:19)
As the Gospel of Matthew is written after Paul, it seems that they contradict each other.