When Yahwehcomes, His purpose will be to execute judgment or literally to bring about crisis upon the ungodly. The idea being communicated is that this judgment is not going to be pretty, as this will be a reckoning. It will be very personal; thus, He is not going to send His angels to do His dirty work. Jesus Himself is going to bring judgment on ALL the ungodly for all the ungodly stuff they have done in an ungodly way, and for all the nasty things that these ungodly sinners have spoken against Him.
The time to choose will have passed. Jesus will prove to all that He alone is good, that He alone is righteous (He is Yahweh Tsidkenu), He alone is Yahweh Adonai (the Lord), and they are not!
