The first thing that came to mind when contemplating this question was an article a brother wrote a couple of decades ago in which he urged that we play it safe and not love our brethren too much. Yet that is the essences of God’s nature and our relationship to Him and our siblings in Christ. Remove the latter and you don’t have the former John tells us. You can’t love too much.
This kind of advice originates in fear motivated by a sectarian attitude. It is a fear which formulates unwritten creeds, divides brethren, stifles open study and the free flow of thought. It enslaves rather than frees.
Brethren will say: “No one says that the use of one cup is wrong, so why not play it safe.” Neither does anyone say that a set order of worship is wrong. Would not celebrating Christmas be the safe route? What about divorce? Relatively speaking, wouldn’t forbidding it be the most safe way to go? This argument is fine when it comes to our opinions, but creates flies in the ointment when you extend it to the opinions of others.
What this attitude boils down to is that it is just another facet of the sectarian stratagem to promote and maintain exclusivism. It is a way to disparage brethren in Christ and regard them as digressives or enemies. They are liberals because they see differently and refuse to bow to the party yoke.
This isn’t the nature of the Christian concept. Did Jesus Christ play it safe when he came to earth? He gave up association with angels to associate with publicans, prostitutes, evil tax collectors, and enemies of God. Those who were trying to play it safe called him “a glutton and a winebibber.” What did Jesus say about the one talent man who played it safe?
Did the apostle Paul play it safe? No! He recognized those of Jewish background who placed an emphasis on ceremonial ritual even to the point of taking a vow with some of them. Yet he recognized those of Gentile background who had no scruples about days and diets and rituals. He crossed lines, so to speak, and did not make personal convictions per se the criteria of brotherhood and unity in the body of Christ.
We can be true to our convictions and use one cup, have no classes, no instrumental music, but to hide behind views in terms of party affiliation excluding those who won’t assert to our unwritten creed for the alleged protection and security such a safe course provides is wrong for many reasons. Would you rather face God on the Day of Judgment having allegedly erred on loving brethren too much or treating them as “brethren-in-error”, digressives, enemies because they refused to play it safe with you?