People don't always pray for themselves. Sometimes it takes supportive friends and family and even strangers to bring a person's needs to God on their behalf when they are either too discouraged, too distracted, or unwilling.
Consider this story: "And when they could not get near [Jesus] because of the crowd, they removed the roof above him, and when they had made an opening, they let down the bed on which the paralytic lay. And when Jesus saw their faith, he said to the paralytic, "Son, your sins are forgiven." (Mark 2:4-5)
It was when Jesus saw the faith of the people who brought paralytic to Him that He healed him.
God has composed His body in such a way that we all have the responsibility and privilege to bear one another's burdens unto Him.