A wise friend of mine told me that a strong bridge of relationship is required to bear the conveyance of weighty truths.
From David Powlison at CCEF:
your first question is not, “Do I have all the right passages to quote?” but rather, “Do I have this man’s ear? Are we in a conversation where the truth can be savory and relevant, and really touch him?”
When someone’s struggling with anger at God, rather than immediately diving into any number of passages of Scripture, make sure you have his ear. Take a walk with him as a friend. Acknowledge the value of his being honest about his struggle with God. Affirm his current conviction that life in a fallen world can be very difficult and deeply disappointing.