I think this is one of the things that keeps JWs locked in. They have absolutely no comprehension of the concept of Grace. They truly believe that they can never be worth of God's love, but at the same time, God expects them to earn his love - the love that they can never be worthy of, even when they are working hard to earn it. Etc, etc, etc. It's the most pernicious example of circular reasoning, and I believe it derails their ability to think critically.
It's not unique to JWs, this subversion of Grace, most of the high control groups teach the same or similar, that you must prove your devotion and earn your salvation. It's quite incompatible with the concepts of Christ-centered christianity, although wholly in line with Pauline Christianity.