Depression/Despair

I've been thinking....How can one who is elect in the Kingdom of God truly be depressed to the point of despair? I understand and do believe there are times in our lives of sadness, always still with the hope of what's to come, but utter despair/hopelessness, how could that be? People argue this with Job's story. I know you can be sad, and Job, was sad, but He trusted the Lord and had eternal hope. I have struggled with depression in my life, and I know that when I felt truly hopeless, and felt like there was nothing to live for, I was not fully trusting the Lord in my trials. Our only hope should come from Christ, and if we are hopeless what is it that we were hoping in?, where was our focus? I am going through a very devastating time in my life right now, and at first, I felt depressed, like there was no hope, but my eyes and heart were not where they truly needed to be, now, though there are times of sadness, my hope is fully in Christ as I continue to keep my eyes on Him,and that gives me great Joy, even in the midst of my sadness. I know God is in control of all things, and all things are for my good and His glory :) God knows what is best for His children. Trust Him.