Strangers are attacking me; ruthless men seek my life – men without regard for God.  Surely God is my help; the Lord is the one who sustains me.

David is being attacked, by men who, he perceives  have no regard for God.  So, he cries out to the One Who can help.   He asks for help from the Lord.  Men who have no regard for God have no morals and no regard for law or justice.  Maybe you work with someone like that, or have a person like that in your family circle.  They are often argumentative and aggressive.  There is only one recourse when they attack: God is our help.  Cry out to Him.