Whenever anyone asks me about the biblical doctrine of election, I always have a standard answer. I tell the person if they are married that if they can explain to me why they married his or her spouse, I will explain to them why God chose us before the foundation of the world. Ultimately why humans love each other and God loves us are both mysterious.
3 Blessed be the God and Father of our Lord Jesus Christ, who has blessed us with every spiritual blessing in the heavenly places in Christ,
4 just as He chose us in Him before the foundation of the world, that we should be holy and blameless before Him—(Eph 1:3-4, NAS).
Personally I believe it is impossible to figure out the doctrine of election; it is just simpler to believe it because the Bible teaches it. Our responsibility is to be overwhelmingly comforted by God's loving kindness toward us. Before time began out of affection for who we are, he chose us. We should enjoy the privilege and not lessen the beauty of election by over examining it. Just enjoy the love behind election!