The idea that your spouse is your soul mate is a very individual-focused way of looking at marriage. Thinking of your marriage as a vocation within the Catholic community may offer the community support that a long term relationship needs.
For Catholics, marriage is a sacrament and a vocation, and married life (ideally) is a visible image of the love that God has for us and the bond that God has with us. While words like sacrament and vocation are increasingly unpopular ways to think about marriage among young people, these traditional teachings may be the better bet to make your relationship last. - Dr Christine Whelan, Busted Halo (click below for full article)