Q: What are some examples of situations in which a marriage can be annuled?
A: Examples include situations in which one or both of the partners refused to get married on God’s terms. In other words, they excluded an essential property of marriage according to God’s definition of what marriage is.
For example, one of the essential properties of Christian marriage is the property of unity, meaning that the marriage is monogamous. If, in one of those countries where polygamy is still practiced, a Christian got married but said in this heart, “I will only take this wife on the condition that I later can take another wife in addition to her,” then the person was not accepting Christian marriage on God’s terms, meaning that he rejected Christian marriage and so was never married in God’s eyes.
More relevant to our society (where polygamy is not practiced), a person might exclude the essential property of fidelity and say in his heart, “Yeah, I will marry her, but only on condition that I can fool around a little later if I get tired of her.” This person rejects the essential property of fidelity, and so rejects Christian marriage, meaning he was never married in God’s eyes because he refused marriage on God’s terms.
Similarly relevant to our society, a person might exclude the essential property of indissolubility in his heart and say, “Yeah, I will marry her, but only on the condition that I can divorce her later and remarry if this doesn’t work out.” Such a person would again being refusing Christian marriage on God’s terms and thus would be refusing Christian marriage.
Finally, a person might exclude the essential property of openness to children and say, “Okay, I’ll get married, but only on the condition that we never have kids, and if I knew we were going to have kids, then I just wouldn’t get married.” Again, an essential property of marriage is excluded, and so the marriage itself is excluded.
Other situations in which there would be an impediment to marriage would be ones in which one or both spouses were psychologically immature to the point of not being able to make a rational commitment to marriage, severely mentally ill, under the influence of drugs or alcohol, had lied about their identity, had lied about their sexual orientation, had lied about their ability to consummate the marriage, etc. Any of these could potentially pose an impediment to the marriage coming into existence in the first place.
Still, the majority of Christian marriages are valid, which is why the Church assumes they are valid until compelling evidence to the contrary is shown.