To make the unknown tongues known, understandable (1 Cor. 14:13). This is the ninth item of the manifestation of the Spirit listed here. However, the manifestation of the Spirit by the believers consists of more than nine items. The apostleship, helps, and administrations by the Spirit listed in v. 28, the seeing of visions and the dreaming of dreams by the Spirit mentioned in Acts 2:17, the signs and wonders referred to in Heb. 2:4, and three of the five miraculous acts prophesied in Mark 16:17-18 are not listed here. The apostle listed here only nine items of the Spirit's manifestation as an illustration. Of these nine gifts and those listed in vv. 28-30, prophecy as prediction, faith, gifts of healing, works of power, speaking in tongues, and interpretation of tongues are miraculous. The rest — a word of wisdom (such as the word of the apostles), a word of knowledge (such as the word of the teachers), and speaking for God and speaking forth God in prophecy by the prophets, discerning of spirits, helps, and administrations — are gifts developed by the growth in life (1 Cor. 3:6-7), like those listed in Rom. 12:6-8, out of the inward, initial gifts mentioned in 1 Cor. 1:7 (see note 1 Cor. 1:71a). The miraculous gifts, especially speaking in tongues and interpretation of tongues, do not require any growth in life. The Corinthians did much speaking in tongues, yet they still remained infants in Christ (1 Cor. 3:1-3). However, the gifts developed in life require growth in life, even maturity, for the building up of the church. It was for this purpose that this Epistle was written to the Corinthians.