Why was religion so important in 1000 AD?

Answer 1

In Revelation 20:1-3 there is a mention of a thousand-year period of time during which Satan will be bound and Christ and his followers will reign uninhibited:

1 Then I saw an angel coming down from heaven, holding in his hand the key to the bottomless pit and a great chain. 2And he seized the dragon, that ancient serpent, who is the devil and Satan, and bound him for a thousand years, 3 and threw him into the pit, and shut it and sealed it over him, so that he might not deceive the nations any longer, until the thousand years were ended. After that he must be released for a little while. (English Standard Version)

This passage of Scripture, which is just a portion of the revealed material that Jesus Christ presented to the Apostle John, has been approached from many different perspectives. Some consider this imagery--including the thousand year period--to be taken completely literally while other considered it to be completely symbolic. There are a number of issues which require some kind of interpretive effort, not least of these is the significance of the thousand years. One school of thought is that Jesus will return and then set up a literal thousand year reign (premillennialism). Another camp says that there will be a thousand year reign of Christ prior to his return (postmillennialism). Yet another perspective says that this thousand year reign is not to be taken literally (amillennialism).

The significance of 100 A.D. is partially that of the anticipation of how this millennial period is/was going to be played out. The early church was mostly of the premillennial persuasion, since it was difficult for them to perceive that Jesus Christ would tary for that long of a period prior to his return. The medieval and reformation church on the other hand tended to be of the other two points of view.