The great covenant promise of the OT is "I will be your God and you will be my people". The irony of the promise is that it is actually quite 'difficult' for God to do it. The tabernacle/temple gives us a 'contradictory' message - "come near/don't you dare come near". It is really very hard to see how a truly holy God can dwell amongst His people. For God the people's sin is offensive, and for the people God's presence is deadly. This 'problem' is only resolved in Christ. In Christ, the great promise is fulfilled and completed. God can not only dwell amongst us, but He is in us. Through union with Christ, God's holiness becomes redemptive and salvific.
But the really striking thing here is that the OT promise is not an individualistic thing, but a corporate thing. It is addressed to a community. We are meant to experience God together as a people. So often I think of God's presence in my life, rather than our life. Union with Christ, seen in this way, is about the church, not simply my relationship with God. Jesus speaks to us collectively "I wll be your God and you will be my people." So, to know this covenant promise being worked out in "my" life, I must see "my" life as part of a "we". The great blessing of knowing Christ is a corporate experience.