NITY can be a good thing... unless people are unified in their rebellion against God and good (Psalm 2:2). Then unity isn't virtuous at all. But, what about unity among believers? Well, that's a good thing... except I'm not in favor of doing evil for the sake of unity. I'm certain that God is also opposed to such strategies. Compromise can be useful in politics and in conflicts, as long as cardinal principles aren't sold out for the sake of unity. Sometimes it takes separation and contention to preserve things that are worth fighting for and dying for. Naturally we need to unify with those who agree with us on the truth so that we can militantly oppose the lies of Lucifer. Of course, we can assume that he will have some forces that are unified on his side too. So, unity is not good if we are speaking of some kind of ecumenical hodgepodge of spineless saps who condemn nobody, except those who oppose their amalgamation of error.
Still, unity is not just a minor objective. Christ prayed for unity in His church (John 17:20-22). As the body of Christ works together in unity, the testimony of Christ is strengthened and His claims are verified in the eyes of the indecisive (and opposing) unbelievers whom we are trying to reach and to rescue. Unity is not just a noble goal if it's convenient, it is part and parcel to our ultimate destination. When we see Him, we will be unified around the throne of God. Don't ever imagine that God isn't interested in unity among His children... He is! Jesus pointed out during His ministry that a house divided against itself will destroy itself or will at least be weakened enough that it will be susceptible to destruction from without (Mark 3:25).