We are in what is sometimes called "the now and the not yet."
Christ accomplished so much when he came the first time. Indeed, just before he died, he said, "It is finished." And it was. The cross was the signal, key event that defeated the devil, dealt with sin, liberated creation, created the Church, and opened Heaven.
Because of the cross I am saved from sin, reconciled to God, and delivered from death and the devil. (These are all mine by God's grace and through faith, which appropriates Christ's work.)
But in my experience I still struggle with sin, am sometimes not as close to God as I would like to be, am still subject to decay and will probably die (if Christ doesn't come back first), and the devil still tries to deceive and distract me.
This is the tension of the not and the not yet. When Christ comes back the second time, then all of these things will be fully realized. The work begun at the First Advent will finally be completed at the Second Advent. Or perhaps a more precise way to say it is that the work done at the First Advent will be fully and finally effected at the Second Advent.
In the meantime, I can still cry with Isaiah, "Oh, that you would rend the heavens and come down, that the mountains would tremble before you!" (64:1 NIV)
- In the meantime, I am now free to serve God and not sin (Rom 6:15ff.), but I still sin from time to time (1 Jn 2:1-2).
- In the meantime, I enjoy a rich relationship with my Heavenly Father, but it will be far better when I am at his throne (cf. Ps 16:11).
- In the meantime, the sting of death has been removed (1 Cor 15:55-57), and death does not hold the terror that it once held (Heb 2:14-15), but death still takes people away from me, and I will probably go through it.
- In the meantime, I can resist the devil and he will flee from me (Jas 4:7), but he is nonetheless still on the prowl for a little while longer (1 Pt 5:18) until he is finally silenced (Rev 20:10).
Praise the Lord that we enjoy the fruits of the First Advent! Praise the Lord that there will be a Second Advent!