To finish the explanantion ... two Baptists (one male, one female, of age, etc.) who marry in a Baptist Church according to whatever rules apply there are recognised by the Catholic Church as being validly married. Generally, the Church recognises as valid any marriage entered into according to the standards of whatever belief system the couple subscribed to at the time of their marriage. The general exception to the above is that one cannot cease to be Catholic.
I thought it had to be a Jewish or Christian marriage, not just any belief system.
I do know people who consider any marriage valid, even one before a justice of the peace--a promise is a promise, etc. This differs from the Catholic point of view, but their view of the marriage after it takes place is essentially the same as that of Catholics: no seeking of divorce, and if a divorce must take place, no remarriage.