I think that we're going to need more information here.
Firstly, you've told us that you can post on Facebook (presumably to your own account) on your laptop but what happens if you lend it to him, so that he can log into his account on it? If he can get in via your machine, but not through his, it suggests that the problem is on his own device(rather than at Facebook's end of things). If so, he probably needs to clear his browser's cache. (Instructions available on request; please tell us which web browser he's using though).
If your hubby is locked out of Facebook posting altogether though, it suggests that his account has been blocked for some reason. (Facebook is notorious for locking people out of their accounts for no apparent reason; I joined Facebook, using my genuine details, and didn't misuse it in any way. My account remained active for no more than twenty minutes before I found myself locked out for 'suspicious activity'!). He might need to upload, say, a copy of his pasport to prove his identity. (What error message, if any, does he encounter when he tries to use Facebook?)