I think that really interesting conversations can, and at times should be passionate. It is very evident that we don't always agree. The important thing to remember is that there IS a line we should never cross.
That line is crossed when we profane God's holy things. These could be His Word, His ministers, or His people. Some things should not be touched.
I feel it is absolutely fine to bash ideas and even some man-made doctrines. But it is never okay to slander the things of God. Looking back, there are some discussions I regret being involved in. Not necessarily because I did anything wrong, but because there was no real value in the discussion. (
Philippians 4:8)