The Centrality of Shabbos to Spiritual Growth

Parshat Vayakhel primarily discusses the contribution of the materials used to construct the Mishkan, and the actual construction itself. However, before delving into these matters, the parsha starts off with the command to observe the Shabbos (verses 2 and 3). From the juxtaposition of the laws of Shabbos and the Mishkan, the rabbis learn that the labors required in the construction of the Mishkan are those labors which are prohibited on the Shabbos. Further, from the phrase "ay'leh hadevarim" (35:1), the gemara determines that there are 39 such labors.

What is the significance of the connection between the Mishkan and Shabbos?