Where this mercy is not, there is also no faith.

Where this mercy is not, there is also no faith. For if your heart is in the state of faith that you know your God has revealed himself to you to be so good and merciful, without thy merit, and purely gratuitously, while you were still his enemy and a child of eternal wrath; if you believe this, you cannot refrain from showing yourself so to your neighbor; and do all out of love to God and for the welfare of your neighbor. Therefore, see to it that you make no distinction between friend and foe, the worthy and the unworthy; for you see that all who were here mentioned, have merited from us something different than that we should love and do them good. And the Lord also teaches this, when in Luke 6:35 he says: “But love your enemies, and do good unto them, and lend, never despairing; and your reward shall be great, and ye shall be sons of the Most High: for he is kind toward the unthankful and evil.”

Martin Luther, “Sermon for the Fourth Sunday after Trinity,” Church Postil