As I said, just because the Bible doesn't specifically say there were not instruments doesn't mean there were not any. And because they were rare, doesn't mean in some fellowships, some upper class Greek woman didn't bring her harp or lute to accompany the music.
As Stilly already pointed out, the believers in Eph. 5:19 worshiped with Psalms, and the Psalms are replete with instruments, esp. in the final ones. David played a harp, and wrote those Psalms. As for the actual verses, a look at the Greek is VERY revealing!
"addressing one another in psalms and hymns and spiritual songs, singing and making melody to the Lord with your heart," Eph. 5:19
According to The New Linguistic and Exegetical Key to the Greek New Testament,** the word for singing, is in fact psalmois (ψαλμοῖς) which specifically means:
verb: primarily the plucking of the strings,
noun: used of sacred songs chanted to the accompaniment of instrumental music.
"[SUP]16 [/SUP]Let the word of Christ dwell in you richly, teaching and admonishing one another in all wisdom, singing psalms and hymns and spiritual songs, with thankfulness in your hearts to God." Col. 3:16
Besides, the command in Col 3:16 are to "let the word of Christ dwell richly in you." The verb "dwell" is enoikeo (ἐνοικείτω) is in the Present Imperative Active 3rd person sing. That means the command is that the Word of God is commanded to dwell, live in, or take up one's home in us. But the other verbs, like teaching (διδάσκοντες), admonishing (διδάσκοντες), are present active participles, NOT in the command tense. As for the word "singing" which is a participle in English, it does not appear in the Greek at all! Instead, only the word psalmois (ψαλμοῖς,) once again appears and as we have already seen in Eph. 5:19, this word has the idea of a song WITH musical accompaniment!!!
So in other words, the entire basis of your theology of no instruments, is not scriptural. Paul knew the Greek well, he used the words that specifically expressed what he meant. Greek is a rich language, and these meanings do not come out in the English.
Suffice it to say, your entire theology, based on two verses is in fact not true. Paul used the word Psalmois ψαλμοῖς, because the word actually means singing with INSTRUMENTS!!
My thought is to get someone in your cult who understands the text in Greek, and then you won't make these ridiculous statements which are not based on the Biblical text!
** The New Linguistic and Exegetical Key to the Greek New Testament, by Cleon L. Rogers Jr. & Cleon L. Rogers III, ZondervanPublishingHouse, Grand Rapids Michigan:1998.