Welcome monis1.
Possibly you could ask your husband to explain "legalism" to you (from the Watchtower library).
The word appears only once in the entire wt library (2012).
The article (g79 6/8 pp. 27-28) is really great and reads like a summary of Ray Franz' book "In Search of Christian Freedom".
You could also ask: "Is legalism apostasy?" (Yes it is and the WBTS is guilty as sin).