Sorry but that is not in the Bible, and as such it is just a Christian belief that came about from a misunderstanding of the Bible.
As i have told you repeatedly, Jesus won't be doing any more work on Earth, because Jesus is not coming back to Earth, according to the Bible.
John 14:19 Yet a little while, and the world seeth me no more; but ye see me: because I live, ye shall live also.
John 17:4 I have glorified thee on the earth: I have finished the work which thou gavest me to do.
John 17:11 And now I am no more in the world, but these are in the world, and I come to thee. Holy Father, keep through thine own name those whom thou hast given me, that they may be one, as we are.
John 18:36 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.
The thousand year reign is referring to Baha'u'llah. Peace will be established during Baha'u'llah's reign because Baha'u'llah was the Prince of Peace.
Isaiah 9:6-7 For unto us a child is born, unto us a son is given: and the government shall be upon his shoulder: and his name shall be called Wonderful, Counsellor, The mighty God, The everlasting Father, The Prince of Peace. Of the increase of his government and peace there shall be no end, upon the throne of David, and upon his kingdom, to order it, and to establish it with judgment and with justice from henceforth even for ever. The zeal of the Lord of hosts will perform this.
Baha’is believe that Baha’u’llah was the Prince of Peace because world peace will be established during His religious dispensation. Baha’u’llah set up a system of government and it has already been established among the Baha’is. The institutions of that government are fully operational, but still in their infancy. They will be more developed in the future as the prophecy says (increase in government).
Isaiah 11:6-9 The wolf also shall dwell with the lamb, and the leopard shall lie down with the kid; and the calf and the young lion and the fatling together; and a little child shall lead them. And the cow and the bear shall feed; their young ones shall lie down together: and the lion shall eat straw like the ox.And the sucking child shall play on the hole of the asp, and the weaned child shall put his hand on the cockatrice' den. They shall not hurt nor destroy in all my holy mountain: for the earth shall be full of the knowledge of the Lord, as the waters cover the sea.
What this means to a Baha’i is that In the future diverse religions and races will become comrades, friends and companions. The contentions of races, the differences of religions, and the barriers between nations will be completely removed, and all will attain perfect union and reconciliation. Eventually, there will be only one religion, the religion of God.
Clearly, Jesus did not fulfill Isaiah 11:6-9 but Jesus promised to fulfill Isaiah 11:6-9 when He returned.
John 10:16 And other sheep I have, which are not of this fold: them also I must bring, and they shall hear my voice; and there shall be one fold, and one shepherd.