To be non-denominational means to follow after Christ and His words. "And whatsoever ye do in word or deed, do all in the name of the Lord Jesus, giving thanks to God and the Father by him" (Colossians 3:17). Thus, if one strives to be nondenominational, one would seek the approval of Christ. This makes sense, in light of the fact, that it is Christ who saves. In John 6:68 we read, "Then Simon Peter answered him, Lord, to whom shall we go? Thou hast the words of eternal life." In this verse, Peter asks a question and then answers it, by saying that Christ has the words of eternal life. Hence, if Jesus has the words that save, does it not seem reasonable to turn to His words--the New Testament? Those words we commonly know, from Matthew to Revelation.
To be non-denominational in worship means to practice what Christ has spoken in the New Testament. In John 4:24, Jesus teaches us that "God is a Spirit; and they that worship him must worship him in spirit and in truth." Thus, in the assembly of a non-denominational meeting, one would find:
Teaching: Acts 20:7 and Acts 2:42
Prayer: Acts 2:42; 1 Thessalonians 5:17 and Ephesians 5:20
Singing: Ephesians 5:19 and Hebrews 2:12
Lord's Supper: Acts 20:7 and Matthew 26:26-30
Giving: 1 Corinthians 16:1-2 and Acts 11:29
These teachings, and these teachings alone, make a worship service nondenominational. Additions to the worship service of God would make the assembly denominational in nature. Why? Because the people would be following after their interests or beliefs, instead of the words of Christ.
To be non-denominational would involve the people being one, as Jesus prayed, "Neither pray I for these alone, but for them also which shall believe on me through their word; That they all may be one; as thou, Father, art in me, and I in thee, that they also may be one in us; that the world may believe that thou hast sent me" (John 17:20-21)
As Paul pleaded with the church at Corinth, "Now I beseech you, brethren, by the name of our Lord Jesus Christ, that ye all speak the same thing, and that there be no divisions among you; but that ye be perfectly joined together in the same mind and in the same judgment. For it hath been declared unto me of you, my brethren, by them which are of the house of Chloe, that there are contentions among you. Now this I say, that every one of you saith, I am of Paul, and I of Apollos; and I of Cephas; and I of Christ. Is Christ divided? was Paul crucified for you? or were ye baptized in the name of Paul?" (1 Corinthians 1:10-13). The concept of denominationalism, in the very definition of the word, is contrary to what our Lord prayed for and to what Paul pleaded. To be non-denominational would mean to be one with Jesus and not divided. May we always strive to be right with God and pleasing in His sight.