"There never was anything so perilous or so exciting as orthodoxy." -- G.K. Chesterton
If I were to know everything but love, my knowledge would be worthless. A demon can be a well-ordered systematic theologian; this I get. But let's not fall off the horse on the other side.
We can't be perfunctory about doctrine. When we read what the Bible has to say about bad doctrine -- that it produces sin, that it endangers souls -- and what it says about good doctrine -- that it ought to be held firm and instructed, guarded, and contended for -- we don't get the impression that right theology is just something on a questionnaire to be glossed over or nodded at.
The Scriptures give us no warrant to treat doctrinal orthodoxy like a mere formality.