Bear you one another's burdens, and so fulfill the law of Christ.
He says not "fulfil," but "complete;" i.e., make it up all of you in common by the things wherein ye bear with one another. This man is irascible, thou art dull-tempered; bear therefore with his vehemence, that he in turn may bear with thy sluggishness; and thus neither will he, through thy support, transgress, nor wilt thou offend in the points where thy defects lie, through thy brother's forbearance. So do ye reach forth a hand one to another when about to fall, and one with another fulfil the law in common, each completing what is wanting in his neighbour by his own endurance.
Parallel VersesKJV: Bear ye one another's burdens, and so fulfil the law of Christ.