I have a friend who says it's OK to use instruments in worship because of Psalms. †He says that we are commanded to sing psalms to which he says how can we sing psalms and not believe what it says when David said to praise God with instruments. What can I say to him that would help him understand that we can't use instruments. I already sent him a link to one of the sermons on instruments on the church's web site. Thanks. All help is appreciated.†
"And I testify again to every man who becomes circumcised that he is a debtor to keep the whole law" (Galatians 5:3).
One of Paul's point against enforcing circumcision is that you can't pick and choose commands. If you say you are obligated to follow one law, then you are stating you are obligated to follow the whole. Few people truly desire to live under the law of Moses. "Stand fast therefore in the liberty by which Christ has made us free, and do not be entangled again with a yoke of bondage" (Galatians 5:1).
Using that same line of reasoning, we would find that your friend isn't willing to do what he states. Yes, Psalms 150 talks about the use of instrumental music in the worship of God. If we are to use instruments because David mentioned in the Psalms, then the conclusion is that we must offer sacrifices and burnt offerings: "May He remember all your offerings, And accept your burnt sacrifice" (Psalms 20:3). "I will offer You burnt sacrifices of fat animals, With the sweet aroma of rams; I will offer bulls with goats" (Psalms 66:15). They need to be offered continually: "I will not rebuke you for your sacrifices Or your burnt offerings, Which are continually before Me" (Psalms 50:8). Which means we need to bring back the altar: "Then You shall be pleased with the sacrifices of righteousness, With burnt offering and whole burnt offering; Then they shall offer bulls on Your altar" (Psalms 51:19). But that would mean we need to have a temple: "One thing I have desired of the LORD, That will I seek: That I may dwell in the house of the LORD All the days of my life, To behold the beauty of the LORD, And to inquire in His temple" (Psalms 27:4). That temple has to be located at Jerusalem: "Because of Your temple at Jerusalem, Kings will bring presents to You" (Psalms 68:9).
Your friend will object pointing out that the New Testament says these things have been replaced, to which you can answer: "EXACTLY!" Included in that replacement of worship with instrumental music is worship by vocal singing only.
Thanks a lot for your answer. That was good, though I've mentioned to him before about the Galatians passage that if you bind circumcision then you are a debtor to keep the whole law. He says that he isn't binding it on anyone, he just says we can have them. What could I say to that? I've tried to answer him, but I think I need and little help.
Circumcision was done on a personal basis during the New Testament time. Paul had Timothy circumcised so that Timothy could teach among the Jews unhindered. "Paul wanted to have him go on with him. And he took him and circumcised him because of the Jews who were in that region, for they all knew that his father was Greek" (Acts 16:3). Notice that this wasn't done because of a command of God, nor was it done to please God. It became a personal choice. "For in Christ Jesus neither circumcision nor uncircumcision avails anything, but faith working through love" (Galatians 6:5).
In the same way, if a person wants to play an instrument at home or for entertainment, that is his personal choice. He isn't doing so because it was a command of God or because it pleases God. But this becomes different when instrumental music is introduced into worship. He is then placing his personal choice and saying this supposedly optional act is something God accepts as worship to Him. The question is: Where does God say this? And by placing it in worship, which is required, he makes what he claims is a personal choice and requires it of all who attends the worship.
Notice, though, that your friend's line of reasoning is that God does authorize the use of instrumental music. But when he is shown that he is wrong, his fallback position is that he isn't requiring it of anyone. But if it was commanded by God, then it would be a requirement. The Jews did not have an option to use instrumental music in their worship, they were required to use instrumental music.