So what is the answer?
Christ would have His Church united. Yet, that should never happen at the expense of compromising things that can never be comprised.
Here are some guidelines that I consider in determining with whom to unite and with whom to separate.
1. Is the message preached one of repentance of sin and embracing of salvation won for us by the sole work of Christ Jesus alone, paid for with His own blood upon the cross of crucifixion?
2. Is the message supported through scripture alone? I may disagree with my brother on his interpretation, but we must accept the Bible as the absolute inerrant Word of God. This must be the standard, or else there is no foundation for discussion.
3. Is faith alone all that is required for justification before God? God has given faith, in the first place, to whom He will. Works should never be added as a requirement for justification. Works will follow faith, not the other way around.
4. Does the message preached go out to everyone, adding no stipulation of goodness on the part of those evangelized? God's grace is sufficient to cleanse any sinner of His own choosing. There is no merit won by men, whether by works or by social status that wins any favor with God.
5. Is the message preached glorifying to God alone? In an age of self centeredness, it is becoming increasingly common for sermons to exalt man, or to offer some "life benefit" to its hearers. This may come as a shock to some, but it's really not all about us. It is all about Him.
If the answer to these questions is "yes" for your particular congregation, then, though I might not agree with you on every point, we can have true Christian fellowship. If, on the other hand, you reject one or more of these points, then how can we have any fellowship?
Can two walk together, except they be agreed?
This, my friend, is my take on True Ecumenicalism.