I believe that the Word of God is a Word that is intolerant (basically it’s His way or perish). That being said can you help us understand the difference between man’s tolerance and God’s mercy? I believe them to be on totally different ends of the spectrum. Can God be tolerant? I believe not, but yes He is Merciful.
You’re correct in saying that God is not tolerant of views that deny or dispute His Word. In our time, we are encouraged to be tolerant of all religions, acknowledging the right of others to hold different beliefs. In Old Testament times, this kind of thinking was punishable by death. Deut. 13 is devoted exclusively to the sin of tolerating the worship other gods.
To be merciful is to show compassion or pity. It’s different from tolerance in that there’s no acceptance of the right to hold an opposing view, only a withholding of the consequences for doing so. God is merciful in that he’s patient and long suffering, waiting for the overwhelming evidence of his presence to persuade us that He is who He claims to be. But eventually His patience will be exhausted and His intolerance of other views will will require judgment.