What if you woke up tomorrow and it was not guaranteed that your lungs would remove oxygen from the air and infuse it into your bloodstream?  You can actually do an experiment right now to see what it would be like.  Hold your breath.  For as long as you can, stop breathing.  Despite how crucial is the capillary action of our lungs, it is so commonplace we take it for granted.

Our union with Christ is absolutely crucial, but sometimes it has become so commonplace we take it for granted.  No experiment exists to help us envision what it is like to not be in union with him— to be branches securely connected to the vine.  But imagine if you can not being able to pray.  Imagine not having the constant presence of the Holy Spirit.  Imagine not being assured of your eternal destiny.  All of these things are afforded to us by our union with him.  It is really, truly remarkable that we are bonded deeply in Christ.