Acts 13:33 references Psalm 2; so why is Psalm 2 not as applicable as any book, chapter, or verse in the New Testament?
Acts 2:27 and 13:35 reference Psalm 16:10; so why is Psalm 16 not as applicable as any book, chapter, or verse in the New Testament?
Acts 13:37 references Psalm 49:9; so why is Psalm 49 not as applicable as any book, chapter, or verse in the New Testament?
Romans 13 quotes the ten commandments; so why are Exodus and Deuteronomy not as applicable as any book, chapter, or verse in the New Testament?
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My point? The Old Testament cannot be discounted.
2 Chronicles 29:27 indicates that the musical instruments that preceded and played with the song of the Lord were ordained by David, not God; so no instruments were commanded by God Himself.
However, David was God's voice to the people; and thus, he passed on God's commandments to the people. So those things ordained by David, especially in the worship of God, can be inferred to be commanded by God -- just as the words of Peter, Paul, Luke, John, et al were the voice, and therefore commandments, to us through the scripture we have today.
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How do these two areas tie together? If we believe that the scriptures are God-breathed, that the authors were inspired to write the words of God, then we must pay attention to where the authors were inspired to quote the Old Testament, just as much as we pay attention to the rest. Any references, such as to the ten commandments, must mean that God intended for us to observe these things. With the absence ("silence") of any particular areas, such as musical instruments in worship services, we must not automatically assume that such are no longer used, or "authorized"; we must look at what scripture does indicate (such as, the Psalms were still being observed); and what we know about those things (such as, we know that the Psalms were worshipful, and they were accompanied by music).
I admit I haven't studied the historians, the "experts" on the era and practices of the time. As far as I can see, there is nothing--nothing--that contradicts this conclusion drawn from scripture itself.