"For he chose us in him before the creation of the world to be holy and blameless in his sight. In love he predestined us to be adopted as his sons through Jesus Christ, in accordance with his pleasure and will -" NIV translation
Now, Paul reminds us of how the "church" was established in that God chose each of us as individuals. He chose us even before the world was made and in fact set things for us to do in our lives at that time. Sometimes, it is hard to wrap your mind around that but God really is that big and that much in control! Paul goes on to remind them and us that we are "adopted" into God's family because of His will and not because of anything we are or have done. The Father planned the "church" from the beginning of time and it is very important to understand that being adopted was significant legally. A natural born child could be removed from a will (lose their inheritance) but an adopted child could not. That describes our relationship with God in that we cannot lose our inheritance (salvation).
"to the praise of his glorious grace, which he has freely given us in the One he loves. In him we have redemption through his blood, the forgiveness of sins, in accordance with the riches of God's grace that he lavished on us with all wisdom and understanding." NIV translation
Paul continues by reminding them that Jesus paid for the "church" with his blood. Grace is being freely given something that you do not deserve and that is the way it is with our salvation. God even gave us the ability to understand what Jesus did for us as we could not understand it on our own.
"And he made known to us the mystery of his will according to his good pleasure, which he purposed in Christ, to be put into effect when the times have reached their fulfillment - to bring all things in heaven and on earth together under one head, even Christ." NIV translation
God has made it known that He has given Jesus the authority to rule over everything. He has declared it to be so in the resurrection of Jesus as even death was defeated by Him. You want to know what God's will is? Plain and simple this verse tells us. It also tells us what His will is for our individual lives and that is for Jesus to be in control (the head) of each of our lives here today. You can make that choice and hit the reset button on your life today.