Luther left the Wartburg on March 1, 1522, arriving at Wittenberg on March 6. One of the first things he did was to preach a series of eight sermons, during the week beginning March 9, in an effort to counteract the extreme reforms which had been forced through by Karlstadt and Gabriel Zwilling. Luther was by no means opposed to reform measures, but he held that they should be brought about by persuasion, not compulsion.*
One of those sermons was on marriage, which Luther commences thusly:
How I dread preaching on the estate of marriage! I am reluctant to do it because I am afraid if I once get really involved in the subject it will make a lot of work for me and for others. The shameful confusion wrought by the accursed papal law has occasioned so much distress, and the lax authority of both the spiritual and the temporal swords has given rise to so many dreadful abuses and false situations, that I would much prefer neither to look into the matter nor to hear of it. But timidity is no help in an emergency; I must proceed. I must try to instruct poor bewildered consciences, and take up the matter boldly.
And then of course he does.
*Luther’s works, vol. 45 : The Christian in Society II p. 13.