John Wesley on Idolatry

Q. 47. Do they think it lawful to represent God and the blessed Trinity by pictures and images, and to worship them?

A. Such pictures are not only almost every where received in the Church of Rome, but universally tolerated; (Bellarm. de Imag. 1. 2, c. 8, sec. Ultimo probatur;) and are both recommended as expedient for the people, (Concil. Trid. Sess. 25, de Sacr. Imag. Catech. Rom. par. 3, c. 2, n. 20,) and proposed to them to be worshipped. (Cajetan. in Aquin q. 25, art. 3.)

Rep. There is nothing more expressly forbidden in Scripture, than the making any image or representation of God: "Take ye good heed unto yourselves, (for ye saw no manner of similitude,) lest ye corrupt yourselves; and make you a graven image, the similitude of any figure," Deut. iv, 15, 16. If it had been acceptable to God, he would have chosen a similitude to appear in; but seeing he did not, they were not to presume to make one for him. This is to "change his glory," Rom. i, 21, &c. And "to place such an image in a Christian temple is abominable," saith St . Austin. (De Fide et Symb. c. 7.) And "thus to describe the Trinity, is a deformation of it," saith Cassander. (Art. 21, sec. de Imag.)

Q. 48. Upon what pretence do they make such representations of God?

A. They say, they thereby represent not God, but some of his properties and actions, after the manner they are described in Scripture; as when "the Ancient of days" is said to "sit on a throne, having the books opened before him," Dan. vii, 9, 10; thereby signifying his eternity and infinite wisdom. (Catech. Rom. ibid.)

Rep. But what is this to those images and pictures used by them which have no resemblance in Scripture; such are their descriptions of the Trinity in Unity, as of God the Father like an old man, having the Son lying in his bosom, and the Holy Ghost over his head like a dove?

(2.) God himself never appeared in any form; and so the resemblance in Daniel was only a prophetical scheme, and did no more belong to God than the eyes and ears that are ascribed to him in Scripture.

(3.) God cannot be represented at all, but by such properties and effects: but if an image of God be forbidden to be worshipped, then the image, even by such properties and effects, is forbidden to be worshipped.

Q. 49. But are not such descriptions of God, the way to represent him, as if he was like unto one of us f

A. Such pictures are not without danger to be exposed to such as cannot read the Scriptures, if they are not taught that they are to be taken metaphorically. (Bellarm. de Imag. 1. 2, c. 8, sec. Respondent.)

Rep. Cassander saith, "I wish those from whom this information is to be received, were not the authors of these superstitions;" and he adds, "That the teaching is not enough, without the occasions be removed." (Art. 21, de Imag.) This he saith of all images, but more especially of such as are made to represent God.

(John Wesley, The Works of the Rev. John Wesley)

Also, from Wesley's Explanatory Notes on the Whole Bible:

Commentary on Chapter 20 of Exodus (note: 20:3)

Commentary on Chapter 32 of Exodus (note: 32:5)