Our Gemara on Amud Aleph references a verse regarding which people are exempt from certain forms of military service including someone who just built a home or got married:

Deuteronomy (20:5-7)

וְדִבְּר֣וּ הַשֹּֽׁטְרִים֮ אֶל־הָעָ֣ם לֵאמֹר֒ מִֽי־הָאִ֞ישׁ אֲשֶׁ֨ר בָּנָ֤ה בַֽיִת־חָדָשׁ֙ וְלֹ֣א חֲנָכ֔וֹ יֵלֵ֖ךְ וְיָשֹׁ֣ב לְבֵית֑וֹ פֶּן־יָמוּת֙ בַּמִּלְחָמָ֔ה וְאִ֥ישׁ אַחֵ֖ר יַחְנְכֶֽנּוּ…וּמִֽי־הָאִ֞ישׁ אֲשֶׁר־אֵרַ֤שׂ אִשָּׁה֙ וְלֹ֣א לְקָחָ֔הּ יֵלֵ֖ךְ וְיָשֹׁ֣ב לְבֵית֑וֹ פֶּן־יָמוּת֙ בַּמִּלְחָמָ֔ה וְאִ֥ישׁ אַחֵ֖ר יִקָּחֶֽנָּה

⁦Then the officials shall address the troops, as follows: “Is there anyone who has built a new house but has not dedicated it? Let him go back to his home, lest he die in battle and another dedicate it…⁦Is there anyone who has betrothed a wife, but who has not yet married her? Let him go back to his home, lest he die in battle and another person marry her.”

The Rambam (Shemoneh Perakim 8) makes a fascinating observation regarding these verses and the realm of human existential choice. While we have many ideas in our traditions that imply that our choice of spouse and other matters are completely under divine guidance via Providence, the very notion that one can build a house or get married and then suddenly die during war but also choose to stay home and avoid that fate, implies that human choice is key and not Providence.  After all, the verse clearly implies that depending on if the person chose to stay in battle or not, his fate would play out accordingly.

If man was forced to act based on some pre-existing future, ⁦then the commands and prohibitions of the Torah would become null and void, and the Law would be completely false, since man would have no freedom of choice in what he does. 

Moreover, it would be useless for man to study, to instruct, or attempt to learn a profession or skill, as it would be entirely impossible for him, on account of the external force compelling him, according to the opinion of those who hold this view, to keep from doing a certain act, from gaining certain knowledge, or from acquiring a certain characteristic. 

Reward and punishment, too, would be pure injustice, both as regards man towards man, and as between God and man. Suppose, under such conditions, that Simeon should kill Reuben. Why should the former be punished, seeing that he was constrained to do the killing, and Reuben was predestined to be slain?...If such were the true state of affairs, all precautionary measures, such as building houses, providing means of subsistence, fleeing when one fears danger, and so forth, would be absolutely useless, for that which is decreed beforehand must necessarily happen. This theory is, therefore, positively unsound…It is also necessary to take all the precautionary measures laid down in the Law, such as, … (Deuteronomy 20:5-7) "lest he die in the battle"…

However, the statement found in the sayings of the Rabbis, (Berachos 33b, Niddah 16b, Megillah 25a) "All is in the power of God except the fear of God" is operative and in accord with what we have laid down here. 

Men are, however, very often prone to err in supposing that many of their actions, in reality the result of their own free will, are forced upon them, as, for instance, marrying a certain woman, or acquiring a certain amount of money. Such a supposition is untrue. If a man espouses and marries a woman legally, then she becomes his lawful wife, and by his marrying her he has fulfilled the divine command to increase and multiply. God, however, does not decree the fulfillment of a commandment. If, on the other hand, a man has consummated with a woman an unlawful marriage, he has committed a transgression. But God does not decree that a man shall sin. 

…⁦As regards the theory generally accepted by people, and likewise found in rabbinical and prophetical writings, that man's sitting and rising, and in fact all of his movements, are governed by the will and desire of God, it may be said that this is true only in one respect. Thus, for instance, when a stone is thrown into the air and falls to the ground, it is correct to say that the stone fell in accordance with the will of God, for it is true that God decreed that the earth and all that goes to make it up, should be the centre of attraction, so that when any part of it is thrown into the air, it is attracted back to the centre. Similarly, all the particles of fire ascend according to God's will, which preordained that fire should go upward. But it is wrong to suppose that when a certain part of the earth is thrown upward God wills at that very moment that it should fall.

I know this is not according to the standard teaching you get in yeshiva or seminary.  The typical approach is to believe that your spouse and every part of life is “bashert”, divinely ordained. But, it sounds from this Ramban that really nothing is God’s will other than the basic forces and circumstances of life. However, Rambam in the Guide for the Perplexed gives a more nuanced view, which is subject to much debate and interpretation. There are layers and layers of understanding necessary to do his view justice. In this small space, I will try to give a flavor of what the Rambam is trying to say and why.

In the Guide (III:51) an additional key point is made clear. Divine Providence is dependent on the degree to which a person mindfully attaches his awareness and day to day actions to God and His will. Thus, One person can stumble through life oblivious and be subject to entropic random natural forces, while another person can, through attachment to God, experience minor unconscious prophecies guiding his actions. Therefore, I believe a number of helpful ideas emerge from the Rambam’s view of Providence which can be integrated in a psychological and spiritually healthy way:

 

1. What happens in the world physically and materially to us is often just about the structure of nature and life. It is neither good nor bad inherently, nor does it have to be in and of itself a reward or punishment from God. It simply is the structure of day-to-day life and the nature of physical existence.

2. However, what meaning we make out of what happens to us, and whether we decide to become closer or further from God, or decide to make healthier, more moral choices or less so, is  completely up to us. Furthermore, it is divine providence itself that God designed the world in such a way that humans engage with it, use their free will, grow and feel the healthy and spiritual satisfaction of taking on challenges and living productively. Humans simply feel better and happier when they are taking on challenges and mastering them, not when they are coddled and taken care of (this is discussed in a beautiful way in Guide III:32). Thus in that sense, anything that happens in this world is truly God's will. This is no small thing, and we should be grateful for the wonders and beauties that life really offers us because of how God provided for us, by creating us and the world, and a relatively level playing field to engage in life. 

3. To the extent that one can continue to cultivate mindful attachment to God, that is in daily and even moment by moment focus and fulfillment of His will, it allows for a special channel of divine inspiration and guidance to enlighten us. In so doing, a person may indeed Merit unusual divine protection through being inspired and guided, perhaps even unconsciously, to make health promoting and success promoting decisions. This is something people can experience in everyday life. There are so many ways in which circumstances and events show us what we need to do and how we need to grow, if we keep an open mind and heart.

So, is your spouse bashert?  Yes, and no.  To the extent that you were living with God when you chose your spouse or your spouse chose you, your choices may have been more or less inspired. But right now, regardless, you are no victim of circumstances.  You and your spouse make your circumstances, moment by moment.  We have no control over what happens to us, but we have control over to what degree we will learn from and seek attachment to God and, actually, the people we love.  We truly can make our own heaven or hell, and God is not to blame.