Holy indignation against sin and injustice. Paul commands: be ye angry, and sin not: let not the sun go down upon your wrath (Eph 4:26, quoting Ps 4:4). The verse establishes two truths in tension: anger as such is not sin (Christ Himself was angry in Mark 3:5, John 2:13-17), and anger easily becomes sin if held, fed, or directed at the wrong object. Biblical righteous anger has three marks: it is God-ward in cause (angry at what God is angry at), proportionate in expression (not the rage of fleshly retaliation), and bounded in duration (not allowed to fester past nightfall). James 1:20 names the failure-mode: the wrath of man worketh not the righteousness of God. The Christian man learns to be angry rightly — rare, true, God-aimed — and to let go of the rest.