3 Let us give thanks to the God and Father of our Lord Jesus Christ! For in our union with Christ he has blessed us by giving us every spiritual blessing in the heavenly world. 4 Even before the world was made, God had already chosen us to be his through our union with Christ, so that we would be holy and without fault before him. Because of his love 5 God[a] had already decided that through Jesus Christ he would make us his children—this was his pleasure and purpose. 6 Let us praise God for his glorious grace, for the free gift he gave us in his dear Son!
Having given Christians "every spiritual blessing" means that there is no greater act of love God could ever show us, that would surpass him becoming incarnate as a man and then dying a horrible death for our benefit. That was the ultimate sacrifice.
The rest says that God has chosen Christians to be in-Christ and that he has adopted us as "his children" - meaning that Christians now have God as their father!
Not just our Lord!
So: God has given us the greatest blessing he could possibly give - him being tortured to death for our benefit
And also: He has adopted those of us who are in-Christ. We are now his sons and daughters and he is now our father.
And the good news is that anyone may become a son or daughter of God, by accepting Christ - whose grace and favour is a "free gift" - all you have to do is claim it and then live accordingly
This scripture gives me many reasons to be cheerful
It makes me feel very blessed