Is it permissible to continue speaking with a Christian woman married to a Christian man, with the intention of inviting her to Islam, knowing that her husband would not be permissible for her after her conversion to Islam?

A man is not permitted to converse regularly with a non-mahram woman (a woman he could legitimately marry) due to the sin involved and because it opens the door to fitna (temptation/strife). The sin is greater if the woman is married, as it infringes upon her husband's rights.

The man must make sincere repentance and completely distance himself from this woman, cutting off all ties with her. If the intention of the conversation was to invite her to Islam, this is permissible if one can adhere to the Sharia guidelines. However, it is safer for a Muslim woman who is knowledgeable and strong in her faith to undertake this.

The man should strive to improve himself, complete his virtues, and embark on the path of righteousness. If he is not married, he should seek a righteous Muslim woman to marry.