The Literal Commandment
'You shall keep My sabbaths and revere My sanctuary; I am the LORD.
The Hebrew word translated here as "revere" literally means "to fear", "to revere", or "to dread".1
When we consider the sovereign G-d over all creation dwelling in majesty in the tabernacle it is indeed a place of power, might, and awe. Like we might be in fear and dread around a 10,000 volt high power line, we should have an even greater fear and dread of the Most High dwelling in His sanctuary.
Nadab and Abihu (the sons of Aaron the high priest) did not approach G-d and the sanctuary with the appropriate reverence but offered strange fire before Him and they were consumed by fire that went out from His presence (Levitcus 10:1-2). That pictures the consequence of violating this commandment.