And yet, at that very time, Erasmus, who, as years passed, had come to regret his earlier faults of the pen,[588] was engaged in composing serious and useful works, in which, though not unfaithful to his older style, he sought to defend the dogmas of religion and the authority of the Church. In March his “_Explanatio symboli, decalogi et dominicæ precationis_” was issued at Basle by Froben; another important work of the same year, appearing in the guise of an exposition of Psalm lxxxiv., contained counsels how best to restore the unity of the Church and to root out abuses. Therein he does not deny the duty of submitting to the Church, but recommends both sides to be ready to give and take. When Luther’s little son Hans had, in his Latin lessons, to study some works composed by Erasmus for the young, his father wrote out for him the following warning: “Erasmus is a foe to all religion and an arch-enemy of Christ; he is the very type of an Epicurus and Lucian. This I, Martin Luther, declare in my own handwriting to you, my very dear son Johann, and, through you, to all my children and the holy Church of Christ.”[589] Luther’s pent-up wrath at length vented itself in print. He had received a letter sent him from Magdeburg, on Jan. 28, 1534, by Nicholas Amsdorf, the old friend who knew so well how to fan the flames of enthusiasm for the new teaching, and who now pointed out Erasmus as the source whence George Wicel had drawn all his material for his latest attack on Lutheranism.[590] It was high time, he wrote, that Luther should paint Erasmus “in his true colours and show that he was full of ignorance and malice.” This he would best do in a tract “On the Church,” for this was the Erasmians’ weak point: They stick to the Church, because “bishops and cardinals make them presents of golden vessels,” and then “they cry out: Luther’s teaching is heresy, having been condemned by Emperor and Pope.” “I, on the other hand, see all about me the intervention and the wonders of God; I see that faith is a gift of God Who works when and where He wills, just as he raised His Son Christ from the dead. Oh, that you could see the country folk here and admire in them the glory of Christ!” The letter pleased Luther so well that he determined to print it, appending to it a lengthy answer to Amsdorf, both being published together.[591]