Josephus shows that aionios did not mean endlessness, for he uses it of the period between the giving of the law to Moses and that of his own writing; to the period of the imprisonment of the tyrant John by the Romans; and to the period during which Herod's temple stood. The temple had already been destroyed by the time Josephus was writing.
St. Gregory of Nyssa speaks of aionios diastêma, "an eonian interval." It would be absurd to call an interval "endless."
St. Chrysostum, in his homily on Eph. 2:1-3, says that "Satan's kingdom is æonian; that is, it will cease with the present world."
St. Justin Martyr repeatedly used the word aionios as in the Apol. (p. 57), aionion kolasin ...all ouchi chiliontaetê periodon, "eonian chastening ...but a period, not a thousand years." Or, as some translate the last clause: "but a period of a thousand years only." He limits the eonian chastening to a period of a thousand years, rather than to endlessness.
In 1 Enoch 10:10 there is an interesting statement using the Greek words: zoên aionion, "life eonian," or, as in the KJV, "everlasting life" (at John 3:16 and elswhere). The whole sentence in Enoch is, hoti elpizousi zêsai zoên aionion, kai hoti zêsetai hekastos auton etê pentakosia, "For they hope to live an eonian life, and that each one of them will live five hundred years." Here, eonian life is limited to five hundred years! In the N.T. eonian life is limited to life during the eons, after which death will be destroyed by making ALL alive IN CHRIST, incorruptible and immortal.