Revelation 6:10

And they cried with a loud voice, saying, “How long, O Lord, holy and true, until You judge and avenge our blood on those who dwell on the earth?”

“How Long??????”

Deuteronomy 32:43  Rejoice, O Gentiles, with His people, for he will avenge the blood of His servants, and render vengeance to His adversaries; He will provide atonement for His land and His people.

Mark 9:19  He answered him and said, “O faithless generation, how long shall I be with you?  How long shall I bear with you?  Bring him to Me.”