I can’t say this for sure about your husband, but I’ve experienced it with my own relatives. I believe that lack of use of the sacrament of confession is a symptom of a much bigger problem, which is a lack of faith altogether.
I have had discussions with a few different Catholic relatives about these types of things. They go in two ways. One way it goes is that I cite my sources really well, and I make a great case. But the person I’m speaking with doesn’t accept my sources. Who says the catechism must be believed? Who says the bible means what you think it means? Who says the Bible must be followed to a tee. I can give answer after answer, slowly moving back through the line of authority, until we get to the issue of whether or not there is such a thing as absolute truth, whether or not the statement “God is real” is absolutely true. It comes down to the fact that the person I’m arguing with admits (without being willing to use the term) to being agnostic. If you don’t believe in God, what good will arguing about the Cactechism do? That person is missing the foundation, which must be built before worrying about the roof.
The other way it goes is I make a good argument, but the person I am arguing with shuts down the conversation very quickly. This is a person who hasn’t thought as deeply about the issues and doesn’t have the ability to debate this topic. They are sure that they don’t want you to change your mind though, so they stop talking. This may be a result of agnosticism, or it may be that the person is choosing selfishness over figuring out right from wrong. That person, rather than hearing arguments, needs to have their heart touched, so that they CARE about the arguments.
Ultimately, when faith is lacking, you can be prepared to answer questions when they arise. But often it is a matter of the heart, or a matter of receiving faith as a gift from God, or having the grace to hear what they otherwise wouldn’t. Best thing to do is to live the best you can, to show love, the best you can, and to pray.