No one is justified by keeping the law, but all should obey God. The law is totally revealed by Jesus Christ's teaching. We should all obey Jesus Christ.
If you want to follow Paul only, you are going to run into many walls.
It is paul who says the law is fulfilled, and so many take this to mean it is obsolete.
It is Paul who says the law is confirmed by faith, and it is.
There are many writings of Paul that seem to conflict and so many without understanding will use whatever they select as the final word according to their own interpretation.
No matter of the Word is a person's own interpretation, rather understanding only comes from the Holy Spirit, for the written word alone kills.
When Jesus teaches on any given subject, Paul is confirmed, but Paul will never be understood by the weilders without knowing from God, that is, from Jesus.