Sometimes what seems to be intolerance is an ardent understanding of the truth. One would not give John high marks for tolerance but it was not about personal feelings - it was about orthodoxy. This was not about whether you like or dislike something, or your opinion about the interpretation of Scripture, or your personal experience of God, but the very meaning of Revelation.
How we see God, how we use our whole body and mind to know Him, depends upon the teachings that we have received and hold dear. Logically, truth is truth; it cannot be that it is true in one place but not true another. As we are whole, one communion, as Christ was wholly God and wholly human we must continue to see the whole. One teaching about God is not greater than another teaching. Nor can one teaching overcome and out truth another. We cannot consider the 2nd commandment without considering it within all the other Commandments. There is no cafeteria in Christianity.
So John had little patience for the things which were not orthodox, Islam and Iconoclasts among them. But that did not mean he was unwilling to work with everyone in order to explain the truth. What we must see is John's voice of reason during a historical period of great upheaval. We honor the things of the world like saints and icons, but we do not worship them - that is reserved for God alone.
And finally, while John belongs to the whole Church, in the West we might think of Thomas Aquinas as the John of Damascus of the West!
Of old, God the incorporeal and uncircumscribed was never depicted. Now, however, when God is seen clothed in flesh, and conversing with men, I make an image of the God whom I see. I do not worship matter, I worship the God of matter, who became matter for my sake, and deigned to inhabit matter, who worked out my salvation through matter. I will not cease from honoring that matter which works my salvation. I venerate it, though not as God. How could God be born out of lifeless things? And if God’s body is God by union, it is immutable.
The nature of God remains the same as before, the flesh created in time is quickened by a logical and reasoning soul. I honor all matter besides, and venerate it. Through it, filled, as it were, with a divine power and grace, my salvation has come to me. Was not the thrice happy and thrice blessed wood of the Cross matter? Was not the sacred and holy mountain of Calvary matter? What of the life-giving rock, the Holy Sepulcher, the source of our resurrection: was it not matter? Is not the most holy book of the Gospels matter? Is not the blessed table matter which gives us the Bread of Life? Are not the gold and silver matter, out of which crosses and altar-plate and chalices are made? And before all these things, is not the body and blood of our Lord matter?
Either do away with the veneration and worship due to all these things, or submit to the tradition of the Church in the worship of images, honoring God and His friends, and following in this the grace of the Holy Spirit. Do not despise matter, for it is not despicable. Nothing is that which God has made. This is the Manichean heresy. That alone is despicable which does not come from God, but is our own invention, the spontaneous choice of will to disregard the natural law,—that is to say, sin.
-- From Against Those who Decry Holy Images