We cannot remain faithful and question God’s own faithfulness. His love for those who are in Christ is beyond question. His character is a constant and his love never fails. He is not loving and gracious toward believers at one moment, only to turn into a malevolent deity the next. He never changes.
In this light, it would be sin to question whether God really loves us, or if He is really faithful to his promises. This is not the questioning worthy of a believer, but of an unbeliever.
— Albert Mohler
“Is it Legitimate to Question God?”
(HT: Of First Importance)