What are we warned to do as believers?

Are what we take to be warnings of coming events to be considered communications from our spirit friends? and if so, why are they not given in a way so plain that we may understand them and thereby be able to avoid impending evils?

Warnings may be given plainly in a vision and are often given by spirit friends when they find the necessary conditions. But generally, the warning is set aside as of no importance by the person interested. It is a mere dream, they say, and they will not ponder it. The accident comes on—they suffer and deeply regret that they carelessly thrust aside the friendly warning, but it is too late. 

When the individual is capable of being entranced, then he can be saved from danger or destruction.

—Hafed, Prince of Persia