A friend committed a lot of zina but repented and is on the straight path. However, he is about to get married but has not told his future spouse. Should he disclose it? What if I am asked about his past by his future in laws, should I disclose this knowing that it will end the marriage?

It should only be disclosed if it directly or indirectly affects his future and his marriage with that person. Sins are supposed to be protected from people but in marriage if someone has done something that affects his future he should be honest and tell his wife about it. If it doesn’t affect the future then it’s his decision to tell or not. For eg has the Zina affected the way he will approach the physical relationship with his wife?