He chose us in him before the foundation of the world, that we should be holy and blameless before him.
We make plans, at least most of us. Before we venture into something, we tend to like to consider our options and the potential outcome for each. In fact, the bigger the decision, the more carefully we plan. The last thing most of us want is to charge headlong into something without first thinking it through. So we plan ahead. We try and cover all the bases. We take care to make sure what we are doing so that we do not find ourselves in circumstances from which it will be difficult to extricate ourselves (at least without great loss).
God is a planner. More than that, God was making plans for us before he even spoke the first thing into creation. Before light, before the heavenly bodies, before the firmament, the animals, and plants and trees, God had decided that we might be near him. He had determined that you and I—because of his great love for us—would have the opportunity to receive the gift of holiness. Fallible and fault-filled humanity was chosen by God to “be holy and blameless before him.” That is almost too great to bear. The human mind struggles to grasp the enormity of what God has done, and the fact that God planned it before the first second ticked on the clock.
What we do with this is up to us, of course. God will not force us into accepting his gift. He will not use his power to obligate us against our will. He will surely compel us with his gospel story, and he will love us perfectly and relentlessly. Ultimately, however, God will wait patiently for us to choose what he has already set aside for us.