Isn't Christ supposed to be God? And isn't God supposed to be everywhere? So how can you not be "with" Christ?
Discussion
It's a spiritual thing, being "in Christ". If His Word is in you and you abide in it and live according to it, you are in/with Christ.
I thought the Word was God? How could it fail to be in me?
Well, do you continue in Christ's word/teachings, i.e., live by them? That is what proves whether you are really His follower and whether His word is in you or not.