"Spiritually Weak" is the term for a mental condition a Witness suffers when they are infrequently indoctrinated. One of the worse things for an active Witness to do is to stay a Witness while not practicing the rituals (meetings and field service mostly). The Witness routine involves heavy indoctrination so when one starts getting less they start to feel weighed down.
Witnesses scury about trying to do the best they can. "Doing the best they can" is actually defined by the Watchtower and involves, in part, encouraging infrequently indoctrinated members to start doing more. They perport that the cause of their down mood is because of lack of participation within the Watchtower community. This is a misleading reason to give since it is technically true. The Rank and File member has a co-dependent relationship with their faith and subsequent rituals required to retain "active membership" status. So naturally if the member stops going to meetings they are going to feel a hole in their life. Not necessarily because they have a real connection from God, but mostly because they have broken a habit that they enjoy for supposedly no reason.
Say you loved to run and you run a few miles every morning. Some circumstance changes in your life and it effects the time you usually spend in the morning running. You are naturally going feel empty or like someting is missing once your routine has been drastically effected. It would be foolish to think that your relationship with God has something to do with how much you run, but that's exactly what the Witnesses do.
Staying in the analogy, what if one of your runner friends takes offense to your change in your running routine. They run with you often and are very disappointed that the running time has been reduced or rescheduled. They could actually take a dysfunctional position and think that running with you was the only reason you and that person are friends. That's also a position Witness peers take when a fellow member stops going to meetings as often.
It's a sad state of affairs that the interpersonal relationships within the Watchtower are tied to Watchtower rituals. If the Watchtower wanted to make running every morning a requirement from God they could and they could enforce it with the brutal arrangement of disfellowshipping and there wouldn't be anything anyone could do about it.
The Watchtower is a frightening Organization.
-Sab