In Weakness There Is Strength - Meaning

[Loreena]

They say, "In Weakness there is Strength." I have always wondered what it actually meant. A little confused. What is the exact meaning of this famous line/verse from the bible. 

[SOUL]

Well, in biblical understanding it means to call oneself as weak, that is, weak to do for oneself and that there is strength in relying on God as it's God's strength that man can do anything.