Love itself, indeed, is a duty; and in loving, we fulfil our obligation. When Augustine says, “Love and do what you please,” it is with the maxim in his mind that love is the fulfillment of the law, in the sense that love is in order to duty, and instrument to the meeting of obligation. It is a fundamental mistake to set love and duty in opposition to one another, as if they were alternative principles of conduct. We cannot try a cause between the religion of love and the religion of duty as litigants — as if we were trying the cause between spontaneous and legalistic religion. Love should be dutiful and duty should be loving. What God has joined together, why should we seek to separate? If we could think of a love which is undutiful — that could not be thought of as an expression of religion; any more than a dutifulness without affection. What we are really doing is discussing the affectional and the ethical elements in religion and seeking to raise the question whether we prefer emotion or conscientiousness in religion. The only possible answer is — both. -B.B. Warfield, The Mystical Perfectionism of Thomas Upham