A theist might come to doubt or disbelieve in God's goodness. This is relevant because in such a situation, the believer in God could ultimately abandon relationship with God (consciously or unconsciously1).
A theist might come to grow jealous of God (Perhaps even resenting God).1 This is relevant because in such a situation, the believer in God would ultimately fail to have a loving relationship with God.
A theist might come to forever doubt/resent God for how God handles suffering, perhaps disagreeing with God's reasons or not understanding them.1 This is relevant because in such a situation, the believer in God would ultimately fail to have a loving relationship with God.
A theist might come to be closed off to moral transformation, perpetually loving their own sin over loving God. This is relevant because in such a situation, the believer in God could ultimately abandon relationship with God.1