Praying for others, especially family, helps you overcome any issues in your own life. In Daniel 9, Daniel acknowledges and takes responsibility for the sins of his fellow countrymen, the Israelites, yet Daniel was not guilty of the sins he was taking responsibility for.
...we have sinned and done wrong. We have been wicked and have rebelled; we have turned away from your commands and laws. - Daniel 9:5
The point I'm making is that if you want to be mature in the Lord, you do the things mature believers do.
Old Testament truth always has it's counterpart in the New Testament. Paul speaks of how we should be concerned for the spiritual condition of those around us.
Rejoice with those who rejoice; mourn with those who mourn. - Romans 12:15
...And in Romans 9, we see the full extent of Paul's selfless devotion to his own people, even to the point of being cut off himself.
I speak the truth in Christ—I am not lying, my conscience confirms it through the Holy Spirit— I have great sorrow and unceasing anguish in my heart. For I could wish that I myself were cursed and cut off from Christ for the sake of my people, those of my own race, the people of Israel. - Romans 9:1-4