One of the blessings that God has already blessed us with in Ephesians is that "He predestined us to adoption as sons through Jesus Christ to Himself, according to the kind intention of His will, to the praise of the glory of His grace, which He freely bestowed on us in the Beloved" (Eph 1:5-6). Now, that's quite a blessing, but it needs to be explored.
First, what does He mean, "predestined"? Most of us think of predestination as the Doctrine of Election. But that was in verse 4, so this isn't the same thing. Biblically, what is "predestination"? Let's look at its use in Scripture. In Acts 4, the disciples spoke of Herod and Pontius Pilate and the Gentiles and the Jews doing "whatever Your hand and Your purpose predestined to occur (Acts 4:28). God predestined Jesus's murder. In Romans, Paul writes, "For those whom He foreknew, He also predestined to become conformed to the image of His Son, so that He would be the firstborn among many brethren" (Rom 8:29).In 1 Cor 2:7, he speaks about "God's wisdom in a mystery" as being predestined. And in Eph 1:11, he speaks of us receiving an inheritance because we were "predestined according to His purpose who works all things after the counsel of His will." Note that these are not about who gets saved. I think the most comprehensive definition for "predestination" is "according to His purpose who works all things after the counsel of His will." That is, biblical predestination if whatever happens at all. And that would include Election. David wrote, "In Your book were all written the days that were ordained for me, when as yet there was not one of them" (Psa 139:16). Every day ordained ... that's biblical predestination.
So this blessing of ours is that in God's predestining all that occurs (which, by the way, is not "causing"). In this case, He predestined us to adoption as sons. Now, I know it's a happy thought that we're all God's children, and, in the sense that we're all God's creation, we are, but there is a special blessing found in God' predestining us to adoption. In John 1 we read, "But as many as received Him, to them He gave the right to become children of God, even to those who believe in His name" (John 1:12). This version of "children of God" isn't being created by Him. It is predicated on receiving Him. So there is a special category of people -- believers -- who have been destined in advance to be His children in a special sense. It is "according to the kind intention of His will" and it is "to the praise of the glory of His grace" so it isn't about us. It's about Him. I'm sorry if you don't like the notion of predestination, but it isn't an invention of Calvin. It's God's idea. Learn to love it.