A few centuries before the events in the paragraph below, the church excused the use of images for worship by saying that they did not worship the images themselves, but only God through the images. That eventually changed to worship of the images. And then it was taught that whoever denied the use of images was a heretic.
“Thou shalt not make unto thee any graven image…”
16. I come now to monstrous impieties, which it is strange they ventured to utter, and twice strange that all men did not protest against with the utmost detestation.89 It is right to expose this frantic and flagitious extravagance, and thereby deprive the worship of images of that gloss of antiquity in which Papists seek to deck it. Theodosius Bishop of Amora fires oft an anathema at all who object to the worship of images. Another attributes all the calamities of Greece and the East to the crime of not having worshipped them. Of what punishment then are the Prophets, Apostles, and Martyrs worthy, in whose day no images existed? They afterwards add, that if the statue of the Emperor is met with odours and incense, much more are the images of saints entitled to the honour. Constantius, Bishop of Constantia in Cyprus, professes to embrace images with reverence, and declares that he will pay them the respect which is due to the ever blessed Trinity: every person refusing to do the same thing he anathematises and classes with Marcionites and Manichees. Lest you should think this the private opinion of an individual, they all assent. Nay, John the Eastern legate, carried still farther by his zeal, declares it would be better to allow a city to be filled with brothels than be denied the worship of images. At last it is resolved with one consent that the Samaritans are the worst of all heretics, and that the enemies of images are worse than the Samaritans. But that the play may not pass off without the accustomed Plaudite, the whole thus concludes, “Rejoice and exult, ye who, having the image of Christ, offer sacrifice to it.” Where is now the distinction of λατρια and δυλια with which they would throw dust in all eyes, human and divine? The Council unreservedly relies as much on images as on the living God.
Institutes, Book I, Ch. 11, sec 16. From ccel.org 12/08/19.