What is the difference between icons and idols in churches that permit icons?

Why do churches like the Catholic Church permit icons when idolatry is forbidden?

The simple answer is that they do not consider all images to be idols (just think of photographs), and believe that members of the Church are able to distinguish between a work of art and God without the need for direct enforcement: after all, Catholics believe that the Word was made Flesh, and dwelt among us, and still dwells among us in the form of the Blessed Eucharist, literally God present before us, as He was present before Thomas, who doubted.

Some possible definitions:

• An idol is something worshipped as divine under the mistaken belief that it contains something divine or is itself God.
• An icon is an image that reminds us of good people and events, sometimes viewed during prayer. Some particular images have sentimental value within a culture, and a rich history.

(Some people worship false gods using icons or images. This is idolatry not because they use icons or images, but because give worship to something in place of God.)

Idolatry is an especially internal sin, so the words of Matthew 7:1 are especially pertinent. If someone starts yelling "this is our god", then perhaps we would have good reason to believe that idolatry is being committed. Compared to the typical Catholic who merely looks at something religious to inspire prayer and worship to God.

The objections to using images seem to be:

1. that creating an image of God would be sacrilegious or spiritually improper. There are stories of native tribes that thought photographs stole a person's soul. Tales about vampires present them as having no reflection in a mirror, and as being invisible in pictures. Such views are not of God. They suggest that Jesus was not fully human, and that physical objects can even in principle be used to "trap" the divine. It is sinful and idolatrous to believe that a physical object has this sort of spiritual effect on God.

2. that it is confusing to humans to imagine God so closely tied to the world around us. But Jesus became true man, and was described as being very human in almost everything He did. Furthermore, the Bible depicts God as wrestling with Jacob in Genesis 32.

3. that images in particular are "disrespectful". There is no biblical basis for this point. Humans tell stories and draw pictures. These activities can be directed towards the praise of God, and it seems incoherent to suggest that communicating something through writing featuring God is fine, while images featuring God have something wrong with them (the only basis I can see for such a view is what I describe very negatively in point #1).

4. that there is something wrong with giving any attention to the "physical" world during worship. But this is absurd, because God made the world, and said that it was good. We believe in the resurrection of the body, and the body is "physical" in this way: it is a temple of God. We don't worship our own bodies because of that, but we do believe that physical things are in fact good and can be directed toward the sanctification of men and the praise of God.

5. that if the images remind us too much of other people, we will then turn attention away from God. But the whole of Hebrews 11 is a remembrance of good people. We must put God first, but we must also keep a second place open for people (both living and dead). The Bible on the subject of giving attention to other people:

   Matthew 22:37-40
   ³⁷ He said to him, “You shall love the Lord, your God, with all your heart, with all your soul, and with all your mind. ³⁸ This is the greatest and the first commandment. ³⁹ The second is like it: You shall love your neighbor as yourself. ⁴⁰ The whole law and the prophets depend on these two commandments.”

This is a Catholic perspective from a very devout Catholic.