The Gemara states that it is said (Vayikra 19:30) אֶת שַׁבְּתֹתַי תִּשְׁמֹרוּ וּמִקְדָּשִׁי תִּירָאוּ אֲנִי יְ-ה-וָ-ה, My Shabbosos shall you observe, and My Sanctuary shall you revere, I am HaShem. The Gemara states that the reason the Torah mentions the commandment to observe the Shabbos next to the injunction to revere the Bais HaMikdash is to teach us as follows: One would think that he should revere the Bais HaMikdash itself, so the Torah therefore states, “My Shabbosos shall you observe, and My Sanctuary shall you revere.” The Torah states observance regarding Shabbos and it states reverence regarding the Bais HaMikdash. Just as observance of Shabbos does not mean that one reveres the Shabbos. Rather, one reveres HaShem Who commanded regarding Shabbos, so too regarding reverence of the Bais HaMikdash, one does not revere the Bais HaMikdash. Rather, one reveres the Bais HaMikdash, and out of reverence to HaShem one acts properly in the Bais HaMikdash.
This Gemara is difficult to understand for two reasons. One, the Torah does not state that one should fear the Shabbos, only that one should observe the Shabbos. Second, the Tikkunei Zohar states that the word בראשית forms an acrostic for the words ירא שבת, fear Shabbos (See Demai 4:1 and Raav there). Thus, we see that there is a concept of fearing the Shabbos.
We can answer these questions by suggesting that the Gemara is teaching us a fundamental in Judaism. We do not believe in the sanctity of objects as an end unto themselves. Rather, we say that an object or a person is holy because of the holiness that HaShem proffered upon the object or the person. While we certainly stand in awe of the Bais HaMikdash and it is told that very pious people actually feared the Shabbos, ultimately our fear and reverence is directed towards HaShem. The Torah specifically uses the word תשמרו regarding Shabbos, as the Gemara (Eiruvin 96a) states that whenever the Torah uses the words השמר, פן ואל, they connote a negative commandment. While Shabbos is a time when we demonstrate our love for HaShem and Shabbos contains great spiritual potential, we still must “revere the Shabbos” by remembering that HaShem is the One Who gave us the precious gift of Shabbos and we must follow His dictates accordingly.