There is just so much incredible Scripture that John just hasn't been able to integrate into the whole of his faith.  

Colossians, 1:24, among many others. 

Frayed edges that don't entwine for him; and he's left unsettled. 

It's in this entwining that one gains a unity and a peace in our full Catholic faith, though this "gain" does demand a very generous response from us, once the Holy Spirit helps us grasp it.