In today's Christian meetings, we mostly use the New Testament. But when Paul wrote 1 Corinthians 14:26, there was no New Testament as we know it. What they had was mostly the Old Testament. In the ancient times, the time of the first apostles, although the Christians did not have the New Testament, they had many new psalms, hymns, and songs written according to the apostles' teaching. First Timothy 3:16 was probably a quotation of a short song that was very popular in the apostles' time. When they met together, they used these psalms, hymns, and songs very much. Some teachers would say that psalms also refer to the old psalms in the Old Testament. I do not disagree with this, but I believe they used more psalms, hymns, and songs written according to the apostles' teaching for the purpose of meeting. I am very thankful to God that we have a New Testament and a hymnal. Our hymnal is very good for speaking.
We need to learn to speak the stanzas of the hymns in our hymnal. Hymn #539, "O Lord, Thou art the Spirit," is an excellent hymn for speaking to one another. I enjoy singing this hymn, but we also must learn to speak it. The first two words of this hymn—"O Lord"—will stir up the meeting...