Tertullian, in his Exhortation to Chastity, addresses the subject of remarriage. He deals with the objection that remarriage is part of God's will because everything that happens is part of God's will, by saying we should not understand God's will in a way that removes our free will.
It is not the part of good and solid faith to refer all things to the will of God in such a manner as that; and that each individual should so flatter himself by saying that “nothing is done without His permission,” as to make us fail to understand that there is a something in our own power. Else every sin will be excused if we persist in contending that nothing is done by us without the will of God; and that definition will go to the destruction of (our) whole discipline, (nay), even of God Himself; if either He produce by His own will things which He wills not, or else (if) there is nothing which God wills not. But as there are some things which He forbids, against which He denounces even eternal punishment— for, of course, things which He forbids, and by which withal He is offended, He does not will— so too, on the contrary, what He does will, He enjoins and sets down as acceptable, and repays with the reward of eternity. And so, when we have learned from His precepts each (class of actions), what He does not will and what He does, we still have a volition and an arbitrating power of electing the one; just as it is written, “Behold, I have set before you good and evil: for you have tasted of the tree of knowledge.” And accordingly we ought not to lay to the account of the Lord's will that which lies subject to our own choice; (on the hypothesis) that He does not will, or else (positively) nills what is good, who does nill what is evil. Thus, it is a volition of our own when we will what is evil, in antagonism to God's will, who wills what is good. Further, if you inquire whence comes that volition whereby we will anything in antagonism to the will of God, I shall say, It has its source in ourselves. And I shall not make the assertion rashly— for you must needs correspond to the seed whence you spring— if indeed it be true, (as it is), that the originator of our race and our sin, Adam, willed the sin which he committed. For the devil did not impose upon him the volition to sin, but subministered material to the volition. On the other hand, the will of God had come to be a question of obedience. In like manner you, too, if you fail to obey God, who has trained you by setting before you the precept of free action, will, through the liberty of your will, willingly turn into the downward course of doing what God nills: and thus you think yourself to have been subverted by the devil; who, albeit he does will that you should will something which God nills still does not make you will it, inasmuch as he did not reduce those our protoplasts to the volition of sin; nay, nor (did reduce them at all) against their will, or in ignorance as to what God nilled. For, of course, He nilled (a thing) to be done when He made death the destined consequence of its commission. Thus the work of the devil is one: to make trial whether you do will that which it rests with you to will. But when you have willed, it follows that he subjects you to himself; not by having wrought volition in you, but by having found a favourable opportunity in your volition. Therefore, since the only thing which is in our power is volition— and it is herein that our mind toward God is put to proof, whether we will the things which coincide with His will— deeply and anxiously must the will of God be pondered again and again, I say, (to see) what even in secret He may will. (link)