We need to consider this world as a place we camp in.
1Since all these things are to be dissolved in this way, what sort of persons ought you to be in leading lives of holiness and godliness, 12waiting for and hastening the coming of the day of God, because of which the heavens will be set ablaze and dissolved, and the elements will melt with fire? 13But, in accordance with his promise, we wait for new heavens and a new earth, where righteousness is at home.
14Therefore, beloved, while you are waiting for these things, strive to be found by him at peace, without spot or blemish; 15and regard the patience of our Lord as salvation.
via PC(USA) – Devotions – Daily readings for Thursday, December 3, 2009.
This does not mean, however, that we are to ignore this world. nor rejoice and mourn for what happens.
Psalm 126
1When the LORD restored the fortunes of Zion,
we were like those who dream.
2Then our mouth was filled with laughter,
and our tongue with shouts of joy;
then it was said among the nations,
“The LORD has done great things for them.”
3The LORD has done great things for us,
and we rejoiced.
4Restore our fortunes, O LORD,
like the watercourses in the Negeb.
5May those who sow in tears
reap with shouts of joy.
6Those who go out weeping,
bearing the seed for sowing,
shall come home with shouts of joy,
carrying their sheaves.

