In Ephesians 1:4 Paul has noted the bounty and location of God's blessings. "All spiritual blessings in heavenly places in Christ." He now turns to two great thoughts ...notice them.
"Just as He chose us in Him before the foundation of the world." Notice first of all that the choosing was in Him. ...the antecedent of the pronoun is Christ. Christ is the location of the choosing. Those who are in Christ are chosen. Surely it was not a choosing of individuals...or the invitation of the Lord would be a farce. Whosoever will, would only mean those who have previously been chosen. And that is surely not true. If it is true then we would never have the power of choice, we could not choose to be in Christ. The choosing would be done for us before the foundation of the world. The message of Paul is that God before the foundation of the world... was willing to choose those who would avail themselves of the opportunity of salvation in Christ, thus enter the locality of that salvation, all spiritual blessings, to be in the body of Christ. Those are the chosen. Whosoever will enter Christ are the chosen.
Secondly, notice what he chose concerning us. "That we should be holy." The word "holy" is from the Greek word "hagios" which is "difference" or "separation". A thing which is holy is different from the ordinary. A Temple is different from ordinary buildings. And it is holy because it is different. A priest is holy because he is different from other men. 2 Peter 2:5 "You also, as living stones, are being built up a spiritual house, a holy priesthood, to offer up spiritual sacrifices acceptable to God through Jesus Christ."
God chose the Christian because he is different.
In the first century the early Christians knew they must be different, in fact so different that in all probability they would be persecuted or, at least, hated for being different. We somehow have come to the idea that as long as you go on living a decent, respectable life, it is quite alright to become a Christian because you don't have to be so very different from other people."
But it is a difference that we must manifest within the world. Jesus said that we "are in the world but not of the world." That's a difference. Our difference must be seen wherever we are; at work, at school, in the home, or anywhere else.
Are you different from the world?
Follow up scripture:
1 Corinthians 9:23
1 Corinthians 3:17