You should address why he is saying this. It maybe due to anger, frustration or lack of knowledge. What are his doubts. Don’t give up that easily. Maybe this is Allah’s message to you and a chance to gain reward. It certainly is a test for you. Get him to see a scholar to answer his question. Be patient and keep asking Allah for his guidance for your husband.

Get him to be in good circles
Maybe take him ziyarah or Umrah/hajj
Or perhaps keep encouraging mosque attendance
Or watch Islamic lectures together