In his first letter to the Corinthians Paul authoritatively sets out much truth about the Spiritual Man. Although it is a letter of rebuke and correction, wherein he criticises, condemns and passes sentence upon sin and wrong behaviour, it also contains much edifying instruction. The apostle's finest treatise upon the gifts of the Spirit and their function in the Church is written here, lovingly spoken of in chapters 12, 13 and 14, and related to worship and Church order.
Reading this section with the phrase, 'now concerning (the) spirituals brethren I would not have you ignorant', he ends it with, 'let all things be done decently and in order'. Challenging them to test their spirituality by their response to these commandments of the Lord (14:37) he leaves the Corinthians no alternative but to believe that they were absolutely ignorant if they did not acknowledge divine authorship and authority for the statements they were reading. This strong approach and outright challenge was necessary at that time because the church was no longer spiritual, but carnal.
The Corinthians had been spiritual for a time, but allowing sin to intrude and be openly practised among them, they became unspiritual: as a result they speedily lost their appetite for truth, and eventually all fundamental matters of spiritual life failed.
By the grace of God and at the request of some person or persons at Corinth, Paul wrote this letter to the church there in order to rectify the position. That he succeeded in his aim is clearly shown by the nature and tone of the second letter he wrote to them some time later. Spiritual men everywhere will mourn that the need ever arose for such stern warnings and firm correction, but we may be grateful to our all-wise God that He ever moved the apostle to write the epistle. By His overruling it has come into our hands, bringing a vast treasury of needful truth, which we would not otherwise have known, and yet which we have need to assimilate. In no realm is this more so than in relationship to the gifts of the Spirit.
(From the book - Spiritual Life and Spiritual Gifts)