I have addressed this concept before, but it is worth touching on again. Marriage is a decision by a human being created with free will, just as love is a decision. It is the gift of free will created by God in all human beings that is the most meaningful aspect of love and marriage because it requires a decision on the part of two individual persons to give themselves to the other with a commitment to fidelity, permanence, and openness to life.
This free-will act is one-dimensional to each person, meaning that the requirement is that YOU say "I love you" in the marriage sense, and say "I do" in the marriage ceremony, and that YOU carry out those commitments for the rest of your life, despite anything the other person does. That is why the Sacrament of Matrimony is the only sacrament that does NOT have a priest as the "ordinary" minister of the sacrament. The two individuals are the "ordinary ministers." They give each other their free-will consent and that is when the sacrament is confected.
Again, marriage is a free-will act of the individuals, and the love they commit to is a love that must continue until death, even if the other person decides to no longer do so. This is a tough reality of marriage for people to accept, but it is also the most beautiful. The marriage vow/commitment is meant to provide security for both individuals and the children that come within the marriage. That is precisely why there is no divorce permitted in the Catholic Church. Jesus Himself declared that marriage is indissoluble, and the Church holds true to this teaching by also declaring that a sacramental marriage can never be dissolved. This subject also requires much more expounding than time here permits, but suffice it to say that marriage is in and of itself an institution that two people should not enter into lightly because it requires a commitment to "permanence." That means, I'm sorry to say, that even those marriages that seem to be not-so-great, or where one is no longer in love with the other, are still very much indissoluble marriages. Yes, that is a hardship for the individuals because of the sufferings that come along with a challenging marriage, but there are no guarantees that every marriage will be perfectly happy.
And that is the critical mistake of the modern notion of marriage. People believe they have a "right" to a happy marriage, and therefore feel they have a "right" to divorce someone if things are not going as they want them to. What they don't realize is that God is not so far away in a marriage, particularly a Christian marriage. God has a vested interest in every marriage, and is available to help a marriage if two people are willing to submit to God's will and not their own will. God, however, never guarantees any marriage will always have bliss and great feelings of happiness. On the contrary, all marriages have their ups and downs, and it is the "choice" of the individuals that affects the outcome. A married couple must wake up every day and make a renewed "decision" to love the other, and pray to God for the grace to love perfectly, especially when it is most difficult to do so. And in God's great wisdom, He allows there to be crosses in marriage that are meant to draw the individuals closer to each other and closer to God. That's what makes marriage such a path to sanctity for people. For most people, they are called to the marriage vocation, primarily to make each person a SAINT! They become a saint by living out their commitment to love the other. And we should all know full well that the path of the saint in this life is the way of the cross, in the footsteps of the Master.
Getting back to the dangerous aspect of "soul mate," it is therefore absolutely NOT required that you marry your "soul mate" in order to have a valid and/or sacramental marriage. There really is no such thing as a "soul mate" in the sense of only one person out there meant for each person. The beauty of having free will is that you can choose anyone out there. BUT … once you choose, it is for life, and it forsakes all others until death, and (this is the kicker) at that moment of giving free-will consent at the marriage ceremony, that person IS the only person for you.
I would very much like to see people stop making so much of finding what they believe is the only person out there meant for them, which only serves to put off marriage, which puts off having babies. I would prefer they focus on making a decision (of course, this is primarily on the man, because he is the one who does the asking out on dates, as well as asking for the woman's hand in marriage). It actually wastes time to look for that "one person meant for you" and does not guarantee anything, because there is no way of knowing "for certain" what God's will is, let alone who God wants you to marry. But the fact is God is helping us come into contact with good prospects, but He does not have just one person set aside for us. We do the choosing, God does the blessing of the choice.