I gotta have my orange juice.

[Jesus] ascended into heaven,
  and sitteth on the right hand of God the Father Almighty;
  from thence he shall come to judge the quick and the dead. (Apostles’ Creed)

When will this coming of Jesus be? We cannot know for sure, but the Bible gives us some helpful clues.

One clue is a prophecy made by David:

Yahweh says to my Lord:
“Sit at my right hand,
until I make your enemies your footstool.” (Psalm 110:1)

Jesus will remain seated until his enemies become his footstool. This is an ambiguous image—they may become his footstool either in repentance or in judgment. Closely related to this, we have the great commission that Jesus gives to his church:

Go therefore and disciple all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit, teaching them to observe all that I have commanded you. And behold, I am with you always, to the end of the age. (Matthew 28:19-20)

This has echoes of God’s promise to Abraham that “in your offspring shall all the nations of the earth be blessed” (Gen. 22:18). This promise was partially fulfilled at times in the Bible. For example, Joseph became a father to Pharaoh (Gen. 45:8) and ministered to “all the earth” (Gen. 41:56). Much later, through Esther, God’s supremacy was proclaimed “in every province and in every city” of a global empire, so that many peoples were converted (Esther 8:17).

There is no reason to doubt that the gospel of Jesus (the greater Ahasuerus) will be successful in accomplishing the great commission, as the church (the greater Esther) offers her own life for the world. God declares that it is too small a thing for him to save few people or nations:

[Yahweh] says:
“It is too light a thing that you should be my servant
  to raise up the tribes of Jacob
  and to bring back the preserved of Israel;
I will make you as a light for the nations,
  that my salvation may reach to the end of the earth.” (Isaiah 49:6)

But so far we have no indication of timing, only of context. In Joseph’s case, the entire world came to Joseph in fourteen years. In Esther’s case, many nations were converted in nine months. God made David’s and Solomon’s enemies to be at peace with them in a matter of decades.

However, the Bible gives us a time-related clue in another one of God’s promises:

Know therefore that Yahweh your God is God, the faithful God who keeps covenant and steadfast love with those who love him and keep his commandments, to a thousand generations.(Deuteronomy 7:9)

If we take a generation to be 40 years (the time Israel spent in the wilderness, the reign of a king), then God promises to show faithfulness for 40,000 years. There is some elegance to taking this number, because it makes the old covenant, which spanned 4,000 years, to be a tithe of all of history. However, in other places God speaks of plural thousands of generations (Exodus 20:5-6, 34:6-7, Deut. 5:9-10, Jer. 32:18). And in another case when God lays claim to thousands, we take it to be an understatement, not an overstatement:

For every beast of the forest is mine,
the cattle on a thousand hills. (Psalm 50:10)

So it seems that 40,000 years may be a bare minimum.

Perhaps it is not just the earth, but the universe, that God intends for us subdue.

See also: The future of Jesus