The knowledge of God is of two types. The first is the sort of knowledge that the law preaches, namely, that there is a God, that he is a just judge, that he repays evil for evil and good for good. This kind of knowledge is something that even the Gentiles had to some extent. There has never been a people that has not known that it must have a god, even when it has been ignorant of what god it ought to have. . . . This knowledge of God is necessary, but it is not enough for salvation, because since we are sinners by nature, we get nothing from this knowledge except damnation. We know that God is a just judge. From that basic understanding of God comes all the idolatry in the world that we see among both Jews and Gentiles. It is also the source of the idolatry and ungodliness that we find among the hypocrites, the Muslims and other nations. Because they know that God is a just judge and acknowledge their own sinfulness, they invent various forms of worship in order to placate him and propitiate his wrath* . . . There is, however, another kind of knowledge of God, and this is the kind that the gospel proclaims. It says that God is a merciful Father through Jesus Christ and that he forgives the sins of those who believe in Christ. He counts such believers righteous not because of the merits of their works but only because of Christ by faith. This alone is the true knowledge of God, which is not known to us by nature but is learned through the gospel, whose author is the Holy Spirit. –Johannes Brenz, Explanation of Galatians.