There is absolutely no question that Christians are to obey the Word of God. But again, context is critical. While the Lord was on earth the Law of Moses was binding on all Jews (and His disciples). That is no longer the case. For Christians there are only four directives from the Law of Moses which are binding (Acts 15). The Law of Christ is now in effect and the Holy Spirit enables Christians to obey that Law.
Again while the apostles were on earth and the Bible was incomplete, prophecies, tongues, and supernatural knowledge were all necessary within the churches. But then Paul --speaking prophetically -- said this:
Charity never faileth: but whether there be prophecies, they shall fail; whether there be tongues, they shall cease; whether there be knowledge, it shall vanish away. For we know in part, and we prophesy in part. But when that which is perfect [COMPLETE] is come, then that which is in part shall be done away. (1 Cor 13:8-10)
Now that we have a complete Bible, God does not give any more genuine prophecies (and John made that crystal clear at the end of Revelation).
So getting back to 1 Cor 14:39 -- Wherefore, brethren, covet to prophesy, and forbid not to speak with tongues -- we need to ask ourselves" "In the light of 1 Cor 13:8-10, does this apply in the 21st century or was it for the 1st century?" And the answer should be obvious.
Prophecy is actually divinely inspired words --words of God and words from God (whether spoken or written). So if any church claimed to have a prophet, all of Christendom would need to accept that as the Word of God. But the reality is that there can be no more prophets or prophecies. The same applies to (genuine) tongues. Indeed none of the Apostolic Fathers (whose writings are available from the 1st and 2nd centuries) claimed to be either prophets or tongue-speakers.
The spiritual gifts for today are evangelists, pastors, and teachers (along with many other gifts not related to the ministry of the Word). The OT = Prophets and the NT = Apostles (and Prophets). And the written Word of God is sufficient for all Christian needs (2 Tim 3:16,17).