Idolatry even at Sinai

 Tehilim (78:36-37) 36. Nevertheless they flattered him with their mouth, and they lied to him with their tongues. 37. For their heart was not constant with him, nor were they faithful in his covenant.

Shemos Rabbah (42:8):Even while they were standing at Sinai itself - proclaiming “We will do and obey” - their hearts were intent on idol worship.: They spoke fraudulently with their mouths and lied to Him with their tongues …

Shir HaShirim Rabbah (07:08) Rabbi Berekhya said in the name of Rabbi Levi: In two places, Israel acted deceitfully with G-d. At Sinai, they acted with their mouths but did not act with their heart, as it is stated: “But they beguiled Him with their mouth and lied to Him with their tongue…their heart was not steadfast toward Him”. In Babylon, they acted with their heart but did not act with their mouth, as it is stated: “For He does not afflict willingly”, as it is stated: “A man who is an adversary and an enemy. This wicked Haman”, and made their wound more painful.

Meiri (Avos Introduction): There is a strong emphasis and constant warning in the Torah to stay far away from idol worship since there has always been a strong attachment to it generation after generation. An intelligent person would naturally ask why this error of idol worship has repeated itself generation after generation? The answer is that the average person more readily believes that which he can perceive and comprehend that which is intangible and abstract. Therefore, a person’s nature draws him to idol worship.

Meshech Chochma (Shemos 12:21): It is said about the Jews that they are believers the descendants of believers. However Taanis (5b) notes that non Jews have stronger religious beliefs than Jews - even when their religion is utter nonsense. “The Kittites worship fire and the Kedarites worship water, and even though they know that water can put out fire they have not yet changed their gods but My people hath changed their G d for that which doth not profit.” And even if you want to answer that the faith that is being praised, is believing in things that will happen in the future such as the resurrection of the dead - non Jews also have strong faith in events that will happen in the future. To explain the distinction between Jewish and non Jewish faith, one must note that the appreciation of things such as love, beauty and power are all inherent in a person. The ancient peoples sanctified all these natural powers and placed high value on them and described them as resulting from specific gods. Thus they had a god of beauty, a god of power and a god of love as is well known. A person who personified one of these natural attributes was described as a godly person. Even today, the peoples of the world make images and sanctify these tangible - directly experienced characteristics. Even the Moslems have sanctified the grave of their savior in Mecca and done other things. Consequently, we see that the emotions and senses directly support their faith which is built upon experience and imagery. Thus, non Jewish religious faith is essentially just an extension of natural emotion. That is not how G d conceives religious faith…. In fact, all tangible existence is totally separate from the one Creator. All this is such pure abstract intellectual awareness that Chovas HaLevavos (1:2 Shaar HaYichud) asserts that true service of G d is for either the philosopher or prophet. Nevertheless, all Jews - even without reaching the levels of prophets or even philosophers - truly believe in these pure abstract thoughts of His existence and His unity and they scoff at all that which is entirely based upon natural emotional experience. They understand that faith based entirely on innate human feelings and thoughts is worthless and transient representing only conjecture –G d in the image of man. This is why Chazal state, “How did the Jews merit to recite the Shema which extols the unitary of G d? Because they were descendants of Abraham, Yitzchok and Yaakov.” Because of this knowledge gained from their forefathers - Jews understand this profound abstract philosophical issue and scorn emotion based faith...