By the way, specifically, regarding icons, they are not spiritually forbidden as long as they are not worshipped, which as
@prodromos @Jipsah @MarkRohfrietsch @chevyontheriver @Xeno.of.athens @jas3 and
@Michie can confirm, is not something that is done by correctly practicing members of the Eastern Orthodox, Roman Catholic, confessional Lutheran or Anglican churches (and also I can personally attest the Oriental Orthodox do not do it either) - indeed worshipping icons is prohibited as idolatry by the canonical legislation of the traditional churches.
We Eastern Orthodox in particular get accused of idolatry because we prostrate ourselves before, and kiss, icons, but this is not worship, but rather veneration, the difference being that worship requires sacrifice. Furthermore, when we kiss an icon, all icons either contain a depiction of Christ our True God, the incarnate Logos, or a Gospel Book (Evangelion) - a book containing the four Gospels, essentially the Bible, the written Word, which is a verbal icon of Christ, and that is what we kiss.
We are worshipping Christ by venerating images of those who put on Christ through baptism or martyrdom or through devotion to him, before and after His incarnation (thus we venerate but do not worship the prophets of the ancient Hebrew religion such as St. Elijah, St. Isaiah, St. Daniel, St. Moses, St. Abraham and St. Solomon, among others). St. Elijah and St. Isaiah are particularly venerated within Holy Orthodoxy, both Eastern and Oriental.
The rationale for the veneration of icons can be found in the Ark, which featured sculpted depictions of winged cherubim, and other related religious objects which depicted various things, and in the person of Christ himself, who is the image of the Father, so that anyone who sees Him sees the Father - thus specifically in the Incarnation, the prohibition against attempting to depict the Invisible God ceased because God became visible, and it is proper to depict Him in His incarnation - and also visual manifestations of the Holy Spirit. However we Orthodox are divided on the issue as to whether or not depicting the Father is permitted since we are not sure that anyone has ever seen the Father - the prevailing explanation for the Ancient of Days seen by St. Isaiah is that this was Christ and not the Father, to reconcile it with the statement of St. John that no one has seen God at any time.
The basis for iconography and its legitimacy can be found in the doctrinal explanations of the Second Council of Nicaea, the Seventh Ecumenical Synod, held in 787 AD at a time when Iconoclasts were in control of the Byzantine Empire and were actively destroying icons and persecuting iconodules (which is why so few icons from before that period survive, but thanks to those which did, for example in the house church and nearby synagogue destroyed by ISIS in Dura Europos, Syria, and other things, such as various ancient icons found in catacombs and the icon of Christ Pantocrator and of the Ladder of Divine Ascent at St. Catharine’s Monastery in Sinai, we have proof they existed, and we can assert with confidence that the view of a total prohibition on imagery, which Ellen G. White does not appear to have subscribed to, was unknown prior to the 7th century - it appears to have arrived with Islam, and it was definitely the conviction of Byzantine generals that the Muslims must be winning because of their iconoclasm, which led to Byzantine iconoclasm (it is also a troubling fact that the generals attributed their defeat to divine disfavor rather than to their own incompetence and/or the Empire’s alienation of the Oriental Orthodox Christians through an absurd and unwarranted violent persecution that started in the latter stages of the reign of Justinian, although given that his wife St. Theodora assisted the Syriac Orthodox bishop St. Jacob bar Addai escape this persecution I’m not entirely convinced that the persecution was Justinians idea - palace coups and intrigues were a thing in the Empire).
In the event iconoclasm did not give the Byzantine military what it sought - rather, it recovered militarily for a time after the end of iconoclasm mainly thanks to the medieval superweapon that was Greek Fire, a pyrophoric chemical that could be sprayed onto enemy ships in battle catching them on fire, which was difficult to extinguish - this gave the Byzantines a huge advantage in naval engagements and the formula was a secret known only to the Emperor regarded as a gift from God - Greek fire also was useful as an infantry weapon. Additionally the Empire was able to prolong itself through an alliance with the Armenians, ending the pointless feud with fellow Orthodox Christians whose disagreement only extended to the specific wording used to describe in what way Jesus Christ is fully God and fully man without change, confusion, separation or division (the OO were uncomfortable with the Tome of Leo and preferred the exact words of St. Cyril, “from two natures” as opposed to “in two natures” while agreeing with everything else including hypostatic union and, with the exception of a brief period in the Armenian church, the OOs championed Theopaschitism and Communicatio Idiomatum which came to be the dominant view across all the traditional churches in time, especially the Eastern Orthodox and confessional Lutherans (to the extent that like the Oriental Orthodox, the confessional Lutherans were falsely accused of Monophysitism).
The actual monophysites degenerated into tritheism (which is what happens when one commingles the humanity and deity of Christ - he becomes sufficiently unlike the Father and the Holy Spirit, since if he has a compounded nature he cannot be of one essence with the Father, thus the Nicene proposition of One God, the Father, Son and Holy Ghost, who are of same essence (homoousios) collapses and one either is forced into Arianism or Tritheism, which is what happened with the original Monophysites - the Tritheists being led by John Philoponus in the sixth century in Egypt, after which the sect disappears from view. The Mormons therefore are the modern day heirs to Monophysitism, not the Oriental Orthodox.
Also I would add as proof of OO Orthodoxy the OOs never had a church taken over by iconoclasts - there was an outbreak in Eastern Armenia which the bishops were able to quickly defeat through expeditious preaching.
