In Revelation 20, it talks about Satan being locked up for "a thousand years" and then being free for "a thousand years". I know that the thousand years isn't a thousand years and it is symbolic but was this in the past or is this in the future near the end or after the end or is it currently happening?
St. John describes in the book of Revelation that the devil will be bound for 1000 years.
Rev 20:1 "And I saw an angel come down from Heaven, having the key of the abyss and a great chain in his hand. 2 And he laid hold on the dragon, that old serpent, who is the Devil and Satan, and bound him a thousand years 3 And he cast him into the abyss and shut him up and set a seal on him, that he should deceive the nations no more until the thousand years should be fulfilled. And after that he must be loosed a little time".
Our Church believes that the period of the millennium reign when the devil was bound started when Christ was crucified. In order for Him to be able to free all those spirits that was in Hades, the devil was bound.
Mat 12:29 "Or how can one enter into the house of the strong man, and spoil his goods, except he first bind the strong man? and then he will spoil his house. "
After that, the 70 disciples came back and they were glad with their authority over the daemons and diseases.
Luk 10:18 "And He said to them, I saw Satan fall from Heaven like lightning. "
Luk 10:19 "Behold, I give to you authority to tread on serpents and scorpions, and over all the authority of the enemy. And nothing shall by any means hurt you."
This thousand year reign of Christ represents the period during which Christ will rule over us spiritually.
The Lord repeated many times,
"Jesus answered, My kingdom is not of this world: if my kingdom were of this world, then would my servants fight, that I should not be delivered to the Jews: but now is my kingdom not from hence. Pilate therefore said unto him, Art thou a king then? Jesus answered, Thou sayest that I am a king. To this end was I born, and for this cause came I into the world, that I should bear witness unto the truth. Every one that is of the truth heareth my voice." (John 18:36,37).
The devil will be loosened at the end days, as this will be the desire of the people.