Well, in the Mosaic Law:Numbers 303 If a woman also vow a vow unto the LORD, and bind herself by a bond, being in her father's house in her youth;4 And her father hear her vow, and her bond wherewith she hath bound her soul, and her father shall hold his peace at her; then all her vows shall stand, and every bond wherewith she hath bound her soul shall stand.5 But if her father disallow her in the day that he heareth; not any of her vows, or of her bonds wherewith she hath bound her soul, shall stand: and the LORD shall forgive her, because her father disallowed her.6 And if she had at all an husband, when she vowed, or uttered ought out of her lips, wherewith she bound her soul;7 And her husband heard it, and held his peace at her in the day that he heard it: then her vows shall stand, and her bonds wherewith she bound her soul shall stand.8 But if her husband disallowed her on the day that he heard it; then he shall make her vow which she vowed, and that which she uttered with her lips, wherewith she bound her soul, of none effect: and the LORD shall forgive her.The husband was very much held responsible for his wife in a number of respects, but I don't know exactly what would be meant by him being responsible for her "spiritual wellbeing". From the Apostle:1 Corinthians 14:35And if they will learn any thing, let them ask their husbands at home: for it is a shame for women to speak in the church.The idea being, perhaps, that the husband is responsible for being well versed enough in spiritual matters (and willing to do further investigation where his understanding is lacking) that his wife would have no need to disrupt the group meeting to ask those sorts of questions.But responsible for her spiritual wellbeing in general? As a Brother in Christ is responsible for his Sister, and somewhat more due to the depth of their relatioinship and his position of headship, but there are definately directions in which one could take "Husbands will be held accountable for their wives' spiritual wellfare" that I would not be willing to follow.edit - There's also the fact, as mentioned, that the husband is required to love her as Christ loves the Church. In failing to do so, he would be lying about Christ's love for the church, and conceivably he would be held accountable for any resulting damage to her spiritual health.