I have heard this argument from anti-catholics-in case of annulment, any children from this marriage will become illegitimate because annulment means that marriage have never existed. I was told its “horrible and how can u condone it?”. How do u respond to such statements?
You may politely tell these people that they do not know what they are talking about. In canon law, an attempt at marriage later proven null is still recognized as having been putative while it was being attempted in good faith by at least one party. If children are born to a putative marriage, the children are still legitimate when investigation finds the attempt at marriage was null.
To be specific, refer them to these, especially Can. 1061 §3 and Can. 1137:
**Can. 1061 §1. **A valid marriage between the baptized is called ratum tantum if it has not been consummated; it is called ratum et consummatum if the spouses have performed between themselves in a human fashion a conjugal act which is suitable in itself for the procreation of offspring, to which marriage is ordered by its nature and by which the spouses become one flesh.
**§2. **After a marriage has been celebrated, if the spouses have lived together consummation is presumed until the contrary is proven.
**§3. **An invalid marriage is called putative if at least one party celebrated it in good faith, until both parties become certain of its nullity.
Can. 1137 The children conceived or born of a valid or putative marriage are legitimate.
If you have further questions, post on the Liturgy and Sacraments forum, as they have real experts posting there.