Presence

ת"ר לפי שראה אדם הראשון יום שמתמעט והולך אמר אוי לי שמא בשביל שסרחתי עולם חשוך בעדי וחוזר לתוהו ובוהו וזו היא מיתה שנקנסה עלי מן השמים עמד וישב ח' ימים בתענית [ובתפלה] כיון שראה תקופת טבת וראה יום שמאריך והולך אמר מנהגו של עולם הוא הלך ועשה שמונה ימים טובים לשנה האחרת עשאן לאלו ולאלו ימים טובים הוא קבעם לשם שמים והם קבעום לשם <עבודת כוכבים> {עבודה זרה}

Our Rabbis taught: When primitive Adam saw the day getting gradually shorter, he said, 'Woe is me, perhaps because I have sinned, the world around me is being darkened and returning to its state of chaos and confusion; this then is the kind of death to which I have been sentenced from Heaven!' So he began keeping an eight days' fast [and prayer vigil - GJG]. But as he observed the winter equinox and noted the day getting increasingly longer, he said, 'This is the world's course', and he set forth to keep an eight days' festivity. In the following year he appointed both as festivals. Now, he fixed them for the sake of Heaven, but the [heathens] appointed them for the sake of idolatry.

The obvious question from this passage (Avodah Zarah 8A) is: if Adam realized that such was the nature of the world, that the shortening of the days was not due to his sin, but instead simply the natural way in which the world operates, why did he feel the need to make a holiday to God? If his motivations would have been idolatrous, it would be understandable, but it is specifically stated that Adam acted "for the sake of Heaven." Why make a holiday simply because one mistook a natural event for an act of God?

Perhaps this helps explain why these holidays, in the end, became associated with idolatry. The fact that their institution was not really in direct correlation to an act of God, but instead in celebration of the natural order of the world, caused later generations to lose sight of their original intent. To Adam, it seemed rational to celebrate those days, since he feared Divine retribution for his sins, and felt he had been given a reprieve, even if in actuality, he had not. But future generations, who did not have this fear, took the holidays as simply a celebration of the natural order, and perverted their original intent to idolatry.

It is interesting to note that whenever we make holidays or special occasions, it is always in confluence with a directly perceived act of God. All major festivals, even those related to the seasons of the year, are associated with some Divine act or revelation. Hallel is recited only on occasions where Divine influence is noticeable (and not when it isn't, i.e. Purim). The reasoning would seem to be so that future generations do not misrepresent the nature of the occasion and turn it towards idolatry (or away from God).