“Strange as it may appear at first thought, yet it is no less strange than true, that notwithstanding all the professed determination to live godly, apostates after turning from the faith of Christ, unless they have speedily repented, have sooner or later fallen into the snares of the wicked one, and have been left destitute of the Spirit of God, to manifest their wickedness in the eyes of multitudes.
Good quote - Although the language is strong and I think most LDS members would agree with that quote. It has some merit in the broader interpretation of “faith of Christ,” and therefore could apply to active, inactive, and non-members. If I knew someone in the Church that lost their testimony but kept their faith in Christ, I would not consider them as “destitute” of the Spirit of God. However, a loss of testimony can lead to anger, which often can and does lead to a loss of feeling akin to losing the Christian spirit. Thus you see many former mormons becoming professed athetists.