Not a mistake.

Ephesians 1:3-14 NIV
³ Praise be to the God and Father of our Lord Jesus Christ, who has blessed us in the heavenly realms with every spiritual blessing in Christ.

Every spiritual blessing.  Can you name them all?  Neither can I.  That means we need to keep getting to know God and learn exactly what they are and what benefit they may be to us here on earth.

 ⁴ For he chose us in him before the creation of the world to be holy and blameless in his sight. In love ⁵ he predestined us for adoption to sonship through Jesus Christ, in accordance with his pleasure and will— ⁶ to the praise of his glorious grace, which he has freely given us in the One he loves.

Before the foundation of the world.  Before Genesis 1: 1 when God said "Let there be light."  I was chosen.  Why?  To stand blameless in his sight.

Because he loved me he knew he would adopt me.  How?  Through Jesus Christ. And he did it for his pleasure and will.  He WANTED to do it.  And he gives grace to me because he loves me.

⁷ In him we have redemption through his blood, the forgiveness of sins, in accordance with the riches of God’s grace ⁸ that he lavished on us. 

This is how a Holy sinless God could reach out to sinful me.  Christ's blood redeemed me.  It bought me back.  It was not for anything I did, but that God loved me enough to give me grace. It was not given out in just the right portion, but it was "lavished" on me.  I envision being covered like a coach the gets the Gatorade poured on him after the win.

With all wisdom and understanding, ⁹ he made known to us the mystery of his will according to his good pleasure, which he purposed in Christ, ¹⁰ to be put into effect when the times reach their fulfillment—to bring unity to all things in heaven and on earth under Christ.

God's wisdom, understanding, good pleasure and purpose were all part of the decision to chose me.  Everything will happen in His right timing as well.  Why?  "To bring all things in heaven and on earth under Christ."

 ¹¹ In him we were also chosen, having been predestined according to the plan of him who works out everything in conformity with the purpose of his will, ¹²in order that we, who were the first to put our hope in Christ, might be for the praise of his glory.

Again I see chosen, predestined, plan and will.  There is nothing here that was an oops or an after thought. All of this was done on purpose for his glory.

¹³ And you also were included in Christ when you heard the message of truth, the gospel of your salvation. When you believed, you were marked in him with a seal, the promised Holy Spirit, ¹⁴ who is a deposit guaranteeing our inheritance until the redemption of those who are God’s possession—to the praise of his glory.

When I heard the word and accepted Christ's grace and redemption I received the Holy Spirit.  When God looks at me he does not see the sinful wretch that he called.  He sees His Spirit within and he knows that only that who have been redeemed by the blood of His Son have that Spirit.  That's is our guarantee.  And this too is for his glory.

If you are a child of God and you are feeling down, unloved, unwanted or worthless STOP.  Remember who you really are.  Let the Spirit encourage you through this time.

If you are reading this and you are not a child of God and want to be, then that is God calling you as well. Don't ignore it.  Pray to God.  Admit you're a sinner.  Accept Christ's payment for your sin.  I also encourage you to contact me so that I may be able to help you further.

God Bless.

Edit to Add.  My friend Jennifer said this video is ideal for today's lesson.  I agree.