In the 1st Century church at Corinth tongues and prophecy were being used without order. People were noisily speaking in unknown languages at the same time, without an interpreter to explain what was being said. Unbiblical prophecies were being offered that went undiscerned and untested. So Paul instructs the church as to how these gifts should be used “decently and in order.”
First in verses 27-28, Paul tells the church that these gifts are not of the sort where the person loses all self-control; rather there is a dynamic tension between the Spirit who is giving the gift and the individual who is its vehicle. So there is no reason that in the assembly these gifts could not be used in an orderly fashion.
Secondly in verses 29-33, Paul gives instruction to the church to evaluate these uttered prophecies. Unlike the prophets of the OT, whose words were to be counted as directly from God, the gift of prophecy in the church is to be used with discernment, under the authority of the church. This is very different from practices we see in the modern charismatic movement; if they applied these Biblical restrictions in contemporary charismatic churches, it would immediately reduce many of their abuses and misuses of the gifts.
Thirdly in verses 33-36, while women were permitted to prophesy in the assembly (1 Cor 11:2-16), they were not to be involved in the verbal assessment of prophecies.
Finally as Paul concludes his argument we are struck by the remarkable fact that while Paul considers prophecy to be revelatory (14:30), that it nevertheless holds less authority than the written word, with which it must agree completely or be rejected.