The work of the cross was established before time began. God stands outside of seasons. He dwells from an eternal vantage point that accounts for the whole of history in a moment. This perspective is free from sunrise and sunset. All is accomplished in his beholding.
Revelation 13:8
And all that dwell upon the earth shall worship him, whose names are not written in the book of life of the Lamb SLAIN FROM THE FOUNDATION OF THE WORLD.
God speaks of thing as though they were. Why, because are a reality to him at the present moment. When he speaks something, it is so true, it is already accomplished.
Romans 4:17
(As it is written, I have made thee a father of many nations,) before him whom he believed, even God, who quickeneth the dead, and CALLETH THOSE THINGS WHICH BE NOT AS THOUGH THEY WERE.
Have you ever dropped a bill in a mail box and said or thought, "Done," have you? Well technically it must be taken by a carrier, processed, and sent to the place addressed. Then it is processed by the billing department. Yet in your mind it is done upon mailing. That is the faith you have in the postal service. Should not God have more faith in his OWN WORD?
Isaiah 55:10-11
For as the rain cometh down, and the snow from heaven, and returneth not thither, but watereth the earth, and maketh it bring forth and bud, that it may give seed to the sower, and bread to the eater:
So shall MY WORD BE THAT GOETH FORTH OUT OF MY MOUTH : IT SHALL NOT RETURN UNTO ME VOID, but it shall accomplish that which I please, and it shall prosper in the thing whereto I sent it.
Here is an example of God speaking about a FUTURE EVENT, as though it already happened.
Psalms 69:21
They gave me also gall for my meat; and in my thirst they GAVE me vinegar to drink.
Psalm 22:16
For dogs have compassed me: the assembly of the wicked have inclosed me: they PIERCED MY HANDS AND MY FEET.
Zechariah 12:10
And I will pour upon the house of David, and upon the inhabitants of Jerusalem, the spirit of grace and of supplications: and they shall look upon me WHOM THEY HAVE PIERCED, and they shall mourn for him, as one mourneth for his only son, and shall be in bitterness for him, as one that is in bitterness for his firstborn.
Why is David and Zechariah talking about these things like they ALREADY HAPPENED? Should not they say, "WILL PIERCE, OR SHALL GIVE ME VINEGAR?"
It had not happened yet, and they are talking about it like it is a past event. IT IS TO GOD.
One more example. Paul talks about us being in heavenly places as though it already happened. Give a read.
Ephesians 2:6
And HATH RAISED us up together, and made us sit together in heavenly places in Christ Jesus.
Wait a second, did the rapture already happen? Of course not, but from God's vantage point, all is accomplished.