Proverbs 2 tells us to incline our ear unto wisdom, apply our heart to understanding, cry after knowledge, lift up our voice for understanding, seek her as silver, search for her like hidden treasures, and then we will understand and find the knowledge of God (Proverbs 2:1-7). God says, "My people are destroyed for lack of knowledge" (Hosea 4:6), and He admonishes us to meditate on His Word day and night that we may observe to do all that is written therein.
All things should be done unto edifying. If those present cannot be taught by what is being done, then it shouldn't be done. Just as with the gift of tongues (that was spoken in the church to benefit everyone) so it is with prophecy. Those who listen will learn and be comforted.
The end result of prophecy is to comfort, encourage, edify, strengthen, exhort, stimulate and help. These should be the guidelines for prophecy within the New Testament church.
We, as believers, are given the sole responsibility in ministry to build others up. This takes place in various ways as we walk in love, promote harmony and peace, and seek the true welfare of others. We must prophesy unto the edifying of the church, and speak things that are good and beneficial to the spiritual progress of others.