The Psalmist David said, "I believed, therefore have I spoken."
Many times it is up to us to step out in faith and believe what the Lord promises us in His Word.
In the book of Job look up in Strongs Concordance to get the verse where it says that you will declare a decree and it will be accomplished unto you...
Yes, we need the prayers of others... but if that is all you rely on... someday there may be nobody you can call for help... then it is just you and the Lord...