Is it sinful for a Christian to salute or honor a national flag?
Christians must only worship the God of heaven (Rev. 22:8-9). Yet, we are also commanded to give honor to governmental authorities (Matt. 22:21; Rom. 13:1-7; 1 Pet. 2:17). The “Caesar,” “governmental authorities,” and “emperor” referred to by Jesus, Paul, and Peter would be the same entities which persecuted Christians severely and who would have a hand in their deaths, but Christians were still commanded by God to show honor to them. American Christians need to remember that. One can disagree with policies put forth by those in political office, especially if they go against God’s Word…but that doesn’t give us as Christians a license to blatantly insult them and show them dishonor. Rather, God would have us show our disagreement and disapproval in governmental authority in a respectful, honorable way, and thus show ourselves different from the rest of the world.
God wants us to give honor to governmental authorities. Saluting a national flag reflects honor towards those in governmental authority, not worship. God must come first in one’s allegiances and loyalties (Matt. 6:33); by definition of being first that means there must be allegiances and loyalties that come after God. One pledged allegiance or loyalty to one’s spouse when they got married, for example. There’s nothing wrong with that as long as one does not put one’s spouse as a higher priority than God and thus have a higher allegiance or loyalty to one’s spouse than to God. In like manner, one can give allegiance or loyalty to one’s country and there’s nothing wrong with that as long as God still comes first. Thus, it is not sinful for a Christian to salute or honor a national flag.
That being said, if it violates your conscience and personal convictions, God would have you abstain from doing so (Rom. 14:22b-23). However, be careful not to bind your own personal idiosyncrasies upon others (Rom. 14:13, 22a).