YOu have to because you receive him physically...And he leaves you everyday, physically...You would do well to believe Jesus...
Mat_15:17 Do not ye yet understand, that whatsoever entereth in at the mouth goeth into the belly, and is cast out into the draught?
Mar_7:19 Because it entereth not into his heart, but into the belly, and goeth out into the draught, purging all meats?
Don't you realize why we keep harping on you guys that you must get 'born again'???
That doesn’t quite negate Jesus saying as well “Do this in rememberance of me” at the Last Supper though.