Here is a sample prayer for a brother that you can use as a guide:
Dear God,
I lift up my brother to you today. Please be with him and bless him in all that he does.
I pray that you would give him your strength and comfort as he faces the challenges in his life. Please give him wisdom and guidance as he makes decisions, and help him to know that he is never alone.
May he experience your love and grace in a deep and personal way. Please keep him safe and protect him always.
In your holy name I pray, Amen.