9 This then is the righteousness of God. As it is called, “The Lord's salvation,” not whereby the Lord is saved, but which He gives to them whom He saves; so too the grace of God through Jesus Christ our Lord is called the righteousness of God, not as that whereby the Lord is righteous, but whereby He justifies those whom of ungodly He makes righteous. But some, as the Jews in former times, both wish to be called Christians, and still ignorant of God's righteousness, desire to establish their own, even in our own times, in the times of open grace, the times of the full revelation of grace which before was hidden; in the times of grace now manifested in the floor, which once lay hid in the fleece.
I see that a few have understood me, that more have not understood, whom I will by no means defraud by keeping silence. Gideon, one of the righteous men of old, asked for a sign from the Lord, and said, “I pray, Lord, that this fleece which I put in the floor be bedewed, and that the floor be dry.” And it was so; the fleece was bedewed, the whole floor was dry. In the morning he wrung out the fleece in a basin; forasmuch as to the humble is grace given; and in a basin, you know what the Lord did to His disciples.
Again, he asked for another sign; “O Lord, I would,” says he, “that the fleece be dry, the floor bedewed.” And it was so. Call to mind the time of the Old Testament, grace was hidden in a cloud, as the rain in the fleece. Mark now the time of the New Testament, consider well the nation of the Jews, you will find it as a dry fleece; whereas the whole world, like that floor, is full of grace, not hidden, but manifested. Wherefore we are forced exceedingly to bewail our brethren, who strive not against hidden, but against open and manifested grace.
There is allowance for the Jews. What shall we say of Christians? Wherefore are you enemies to the grace of Christ? Why rely ye on yourselves? Why unthankful? For why did Christ come? Was not nature here before? Was not nature here, which you only deceive by your excessive praise? Was not the Law here? But the Apostle says, “If righteousness come by the Law, then Christ is dead in vain.” What the Apostle says of the Law, that say we of nature to these men. “If righteousness come by nature, then Christ is dead in vain.”
Source: Sermons on Selected Lessons of the New Testament (New Advent)