Many are picking up Psalm 91 these days-for prayer, for study. If you are thinking of doing that very thing, be certain that you trust the source. Are you sure where it came from? Well yes, it’s in the Old Testament. What more do you know about it?
The more you know about the origins of this Scripture, the more profitable it will be for you in prayer and in proclamations of faith. This is an amazingly powerful piece of Scripture, so don’t have it watered down in your life by being half informed.
Read this helpful post on Psalm 91 to fill in some of the blanks for you.
Psalm91prayer's Blog 
Psalm 91 is my life verse! The Lord Most High is my refuge and strength. This verse became particulary powerful and meaningful as I faced the tragic loss of my 22 year old son. So much so that I have written a book about it.