This argument reduces complex religious belief to a single psychological motive. While faith can certainly provide comfort, it is also supported by historical evidence (the life and resurrection of Jesus), philosophical arguments (the cosmological and teleological arguments), and personal experience that goes beyond mere wishful thinking.
The Bible acknowledges that death is an enemy, but faith is not a 'crutch'—it is the 'assurance of things hoped for, the conviction of things not seen' (Hebrews 11:1). Christ's resurrection provides a real, historical hope that transcends psychological comfort.