Orthodoxy is perhaps the only Christian denomination in which icon veneration is highly developed. Moreover, if Catholics treat sacred images with respect, then numerous Protestant churches unanimously accuse the Orthodox of almost idolatry.
In fact, an icon for a believer is not an idol at all, but a reminder of another world, of saints and God. The phrase "worship an icon" carries a slightly different meaning than "worship God." An icon can be compared to a photograph of a loved one, which is carefully kept in a family album or hung on a wall. No one considers a photo an idol or a replacement for the original, even if it receives a lot of attention.
In many religions there are no icons, and any images are prohibited for a very reasonable reason: no one has ever seen God, so how can you depict the indescribable?
Orthodox icon painters also do not invent anything, and, according to the rules, only what was material is depicted on the icons.
But what about the icon of the Holy Trinity, because no one has ever seen God! This is not entirely true. We saw our God in human form. Jesus Christ is God and man. So at least the second Person of the Holy Trinity can be depicted. Had some incarnation and the Holy Spirit. He appeared several times as a white dove. It wasn't a real dove, of course, but it could be written that way.
So, the two Persons of the Trinity are depictable, but God the Father is missing for completeness. The icon "Holy Trinity" cannot exist without the Father.
Icon painters have found several ways out of this situation - more or less successful. For example, there is an icon of the Holy Trinity, a photo or reproduction of which is in every prayer corner. On it, God the Son sits on the throne, above Him is God the Holy Spirit, and God the Father is indicated by a certain sign of outpouring grace. There is another option, which is commonly called Catholic, where God the Father is depicted arbitrarily as an old man, and God the Holy Spirit as a dove. Everyone admits that the icon is non-canonical, that is, it does not comply with the Orthodox rules of icon painting, but it was widely used as early as the 19th century.
The most famous icon of the Holy Trinity was painted by Rublev.
This depicts a moment from the Old Testament story when three angels came to Abraham. According to the interpretation of the holy fathers, this was God, or maybe Andrei Rublev used only an image. In any case, an icon is a unique work not only of icon painting, but also of theological thought. Rublev's "Holy Trinity" icon is not only that moment at the tent of Abraham, but also eternal advice. This idea is suggested by the contents of the bowl on the table. In it (according to many interpreters) is the sacrament, that is, the Blood of Jesus Christ. This is the moment of a certain prophecy about the future, about the incarnation of the Son of God and about His suffering. It is this mysterious meeting that is called the eternal council.
The icon of the "Holy Trinity" is mysterious, it has a huge number of symbolic details, by which it can be determined that Andrei Rublev designated a certain Person of the Holy Trinity with each Angel. Discussions about it are still ongoing. This image is now kept in the temple at the Tretyakov Gallery. Here he is under protection, but you can venerate him, pray to God and light a candle.
