Summary: Paul introduces our election in Christ as a done deal
Ephesians 1:3 Blessed be the God and Father of our Lord Jesus Christ, who hath blessed us with all spiritual blessings in heavenly places in Christ: 4 according as he hath chosen us in him before the foundation of the world, that we should be holy and without blame before him in love: 5 having predestinated us unto the adoption of children by Jesus Christ to himself, according to the good pleasure of his will, 6 to the praise of the glory of his grace, wherein he hath made us accepted in the beloved.
Verses 1-14 constitute one very long sentence. If Paul had run this past a writing teacher today it would have been marked down as a run-on sentence. But Paul has one big point to make, and can't stop till it is made: our salvation is God's work, and based on His choice, not ours.
Some people like to argue about things. They talk about what they see as a contradiction between all the places the Bible teaches we have free will with passages like this that teach we were chosen since before the foundation of the world. There is no contradiction.
Boethius dealt with the issue of free will verses foreordination more than one thousand years ago. In his story, Lady Philosophy takes him on a little thought experiment. They watch a chariot race together. The charioteer is coming to a corner and must turn to the left in order to avoid hitting the wall. Lady Philosophy asks if Boethius knows what the charioteer is going to do. He said, "Yes. He will soon turn his chariot to the left". The charioteer turns left. Lady philosophy asks if by knowing what the charioteer is going to do Boethius forced him to turn left. "Of course not." Boethius replies. Neither does God force us to do anything when, knowing we will choose Him, He chooses us. We are chosen since before the foundation of the world. He gives us free will and allows us to choose. There is no contradiction.
If you were God, and you lived outside time, you would see all history as currently existing. I like to think of it this way-our current observation equipment can record light from billions of lightyears away. Since the light traveled billions of years to get here we are seeing the past of those distant galaxies. If some creature in those galaxies were looking back at us, they wouldn't see us. They wouldn't see the earth or, if distant enough, wouldn't even see our sun. They would see the Milky Way galaxy as it was billions of years ago. What if you were at all locations in space? What if you could skip the inconvenience of travel? The Bible teaches that God is all places (Psalm 139). So He is present at all places now, even though light from distant locations is showing only the past--That means He is also at all times. So, omnipresence also means omnitemporality. God is at all places and at all times. So when He introduces Himself to Moses He simply says "I Am that I Am". Jesus said, "Before Abraham was, I AM". He is, now, occupying all times. He also inhabits eternity, meaning He is not limited to time or place. Lacking the limitations of time, and having access to all knowledge, God knows all history, all the things we think of as not yet happened, as well as all the things that have already happened, and all that is happening now. So, God is able to choose from a very different perspective than ours. And He chooses based on that knowledge (Romans 8:29). If you suddenly knew the future, and knew the numbers that would be chosen in the Lottery, would you choose losing numbers? If you knew which horse would win in a horse race, would you bet on a loser? God chooses us. Which means we are already winners, even if it doesn't seem like it sometimes.