Gerhard and Walther

Humility is the true, solid foundation of every Christian virtue. Just as one is unable to construct a building without a foundation, where there is humility, everything is in vain if one thinks he can carry out the construction of godliness. For with humility a person turns away from himself, so that he does not highly regard himself or secretly make himself a god.—Johann Gerhard, Schola Pietatis III:213.

God had to send us His love before we could know what it is to love our neighbor. Thus, if we are still unmerciful, it is a sign that we do not stand in faith.—C. F. W. Walther, God Grant It!, p. 537.