"Thou shalt not make unto thee any graven image, or any likeness of any thing." (Exodus 20:4)
There are several reasons why idolatry is forbidden. The most obvious is that the triune Creator is too great to attempt to visualize (Exodus 34:5-7). There is no thing or experience in human existence that can represent the immortal and invisible Creator (1 Timothy 6:16).
Thus, God sees any effort to "picture" Him (idolatry) as rebellion (Jeremiah 5:19-25). It does not matter how we may attempt to "see" God. "Any likeness of any thing that is in heaven above, or that is in the earth beneath, or that is in the water under the earth" (Exodus 20:4) are all totally incapable of expressing God's person.
Romans 1:18-32 reveals the heart of an idolater. Those who hold the truth in unrighteousness (v. 18) will not glorify God as God (v. 21), even though they know Him by the creation itself (v. 20). Instead, they change God's inestimable glory into an earthly creature (v. 23) and consciously change God's truth into a lie (v. 25).
Thus, by open choice and willing rebellion, idolators worship and serve the creature rather than the Creator (v. 25), thereby abandoning God for a despicable and unnatural lust, for an ungodliness that, in turn, causes them to despise the very thought of God in their knowledge (v. 28). Ultimately, the only pleasure they can find is among other idolaters (v. 32).
Paul taught the "philosophers" in Acts 17:22-29 that the heart of idolatry is rejection of God as Creator. Idolatry, in any form or practice, strikes at the heart of salvation, because "he that cometh to God must believe that he is, and that he is a rewarder of them that diligently seek him" (Hebrews 11:6). HMM III