How can repentance and forgiveness of sin be accepted after committing adultery and selling gold, with the fear that the husband will not forgive, and what measures should be taken?

Indeed, for a woman whom Allah has blessed with a righteous husband, Allah has bestowed upon her a great favor. For a woman to fall into indecency is a grave betrayal of her husband and an act of ingratitude for this blessing. It is one of the most heinous sins. Allah Almighty says: "So righteous women are devoutly obedient, guarding in [the husband's] absence what Allah would have them guard."

No matter how great the sin, Allah accepts repentance. Allah Almighty says: "Say, 'O My servants who have transgressed against themselves [by sinning], do not despair of the mercy of Allah. Indeed, Allah forgives all sins. Indeed, it is He who is the Forgiving, the Merciful.'" Sincere repentance erases the effect of the sin, and the one who repents from a sin is like one who has no sin.

Repentance involves abandoning the sin, regretting it, and resolving never to return to it, while concealing oneself and not openly declaring the sin.

You must clear your husband's brother of the theft accusation without informing him of the transgression. It is permissible to use allusions and circumlocution for this.

If your repentance is sincere, then adhere to it and close the doors to temptation. Do not inform your husband or anyone else about what happened. Increase your righteous deeds and good actions that erase sins.