Some will say, “You make too much of non-essentials.” That is a thing I frequently hear—non-essentials! There are certain things in Scripture, they tell us, that are non-essentials, and therefore they are not to be taken any notice of. Doctrinal views, and the Baptism of Believers, for instance—these are non-essential to salvation, and therefore, is the inference which follows according to the theory of some—we may be very careless about them!
I think you would find it to be non-essential for you to keep her any longer, but extremely essential that you should discharge her! And what shall we say of those men who put aside the words of Christ, and say, “His precepts are quite non-essential”? Why, I think because they are non-essential, they therefore become the test of your obedience! If you could be saved by them, and if they were necessary to your salvation, your selfishness would lead you to observe them; but inasmuch as they are not necessary to your salvation, they become tests of your willingness to obey Christ!
~ Charles Spurgeon, sermon #359