“If any man think himself to be a prophet, or spiritual, let him acknowledge that the things that I write unto you are the commandments of the Lord” (1 Cor. 14:37).
Many Christians have a fuzzy idea that when Christ ascended up from the Mount of Olives to heaven, He stopped speaking. But nothing could be further from the truth! Paul says that the things he wrote to the Corinthians, and to the Body of Christ as a whole, were the “commandments of the Lord”! Similarly, in his epistle to the Thessalonians, Paul says, “For ye know what commandments we gave you by the Lord Jesus” (1 Thes. 4:2).
After Christ ascended to heaven, Israel continued in her rebellion against God by rejecting the Holy Spirit’s ministry through the twelve. Thus, Israel was temporarily set aside by God (Acts 7). God then raised up a new apostle, and gave Him a message which had never before been revealed (Acts 9; Gal. 1:11,12). Christ spoke again!
From heaven the glorified Christ gave to the Apostle Paul a new revelation concerning His heavenly ministry to the Church, the Body of Christ. To Paul, the apostle of the Gentiles (Rom. 11:13), was given the commandments of Christ for the Body of Christ today. In Paul’s epistles, we have the will of God for our Christian lives during the dispensation of the grace of God. In Paul’s letters, we find the doctrines of grace that the Church is built upon and is to live by and share with the world.
Notice that Paul’s words, as revealed to Him by Christ, are spoken of as “commandments.” This is not a take-it-or-leave-it word. When a commandment is given by God, He expects us to obey and conform our wills to His will. In past dispensations, other commands were given which were valid at the time given, but are not for today, and are not for our obedience.
Take food for example (a topic close to my heart). The Bible commands man to eat only vegetables and fruit, then it allows for eating meat with fruit and veggies, then it commands only certain foods to be eaten, then it commands that all food can be eaten. It is impossible to obey all of these different commands at the same time.
There are many other issues in Scripture like this, so it’s imperative to determine which commands God would have us obey today. The answer is that Paul’s letters are the commandments of the Lord which are valid for today under grace. And Paul says we can eat all things (1 Tim. 4:3-5). It’s great to live under grace! source