The passage I quote from Revelation, along with most of the letters of the NT, clearly indicate that there were beliefs and behaviours in the church which were wrong. These should be confronted, not tolerated.

The questions which follow are:

1) Is this behaviour over the line?
2) How should the church challenge it?

and I'm not trying to argue those points now, just reminding us that they are live issues.

If the statement 'who am I to judge?' becomes an excuse for Church leaders to duck out of their responsibility to challenge what they know to be wrong, then the Revelation passage makes it clear that they are failing Jesus. The issue for the individual is more nuanced, though ultimately I believe we must be clear in making a gentle(!) stand on issues. And we must be very conscious of the power of group think - if we hang around long enough with people who think what we are tempted to think, then we will tend to come to agree with them. Or as Paul puts it 'Bad company destroys good morals.'