It is important to learn the lessons of the building of the ארון קודש, the holy Ark. There are two specific ideas learned here.
The first is that the measurements were half measurements. They were two and a half cubits by one and a half cubits. The Rabbis explained that the reason for this was to teach how we are incomplete and need to constant work on self improvement. This is a lifelong task to try to grow and go higher in spirituality.
The other lesson is that the Ark had gold on the inside and outside. This was to teach that one should not be אחד בפה ואחד בלב, one way in one’s mouth and another in one’s heart. We are not to be fake or hypocritical. We are to be honest and truthful in all that we do. Two important lessons from the holy Ark.