The Son of God entered Time specifically “to destroy the works of the Devil” (1 John 3:8b). Was He successful?

Yes. Messiah Jesus effectively destroyed death, Hell, the grave, at Golgotha by selfless love for those who believe in Him as Lord by covenant promise and the Devil is now being used in these last days by God to separate wheat from chaff; sheep from goats; the faithful from the unfaithful; this, as this entire debacle in Time is an object lesson for the faithful angelic creation that remain in the Kingdom in servitude to God that faithfulness, loyalty, obedience, are essential for peace and harmony to exist among the brethren and the object lesson of horror upon the Earth over the previous 6000-years will be an effective deterrent, a bulwark, against future rebellion as free will remains extant by necessity.