Commandment about idols and idolatry in OT

God continually tells people throughout the Hebrew Bible to not turn to idolatry. Exodus 20:4: >“You shall not make for yourself a carved image, or any likeness of anything that is in heaven above, or that is in the earth beneath, or that is in the water under the earth." Does this mean that they should not try to understand what God "looks" like by trying to recreate an image of Him (we are finite minds, God is an infinite mind), or that they should not make such images because that would lead them to venerate nature gods? Because the Israelites do make carved images of something that is "in heaven above," namely angels (cherubim): God tells Moses to place cherubim on the Ark. So then the making of images mentioned in Exodus 20:4 (and other laws concerning idolatry) does not pertain to, for example, making an image of Jesus or making images of various Saints, because those figures are, (in the Christian sense), a continuation of the OT, and thus they are beings created "in the image of God"? What is actually meant by all this? To not make images of various things for worship because they were not created "in the image of God"? (God is above, beyond, and outside of nature, and equating God to nature images by creating what is "in heaven above, or that is in the earth beneath" is offensive to God?) Because, once again, didn't God tell Moses to place Cherubim on the Ark?