Ephesians 1:4-5: “According as he hath chosen us in him before the foundation of the world, that we should be holy and without blame before him in love: Having predestinated us unto the adoption of children by Jesus Christ to himself, according to the good pleasure of his will,”
Before the world was created, God chose us (saved Christians) to have access and blessings that God has for us. The Calvinists ruin this blessing. Calvinism teaches that God’s election is based on who will be saved and who will be lost. That is a cruel God. The truth is that God has offered salvation to everyone.
A Calvinist might use verse 4 to defend their doctrine. The simple answer is that God us (“us” being the ones in Christ) to receive spiritual blessings (verse 3) and be holy and without blame before him in love. For example, a Catholic who does not receive Christ as their savior because they want to be their savior by doing works for salvation will not receive spiritual blessings and be blameless.
There is always a condition. For example, in verse 4, the condition is that they are in Jesus Christ (verse 3). That is why God does not see any more sin in us, because He loves those who are in Christ. It’s also a great verse for eternal security.
A Calvinist might say, we are in Christ before the foundation of the world. That is a silly thing to say, then that means we were in Christ, and when Adam sinned, we went in Satan and then back in Christ.
Verse 5 is also a Calvinist favorite with wording such as “predestinated.” “Predestinate” means one’s destiny is already made before something happens. A Calvinist will say that they are predestinated for salvation, but that is false as it’s not in the context of salvation.
“Having predestinated us unto the adoption of children by Jesus Christ to himself”
The predestination is that you become God’s children based on the condition that we are in Christ. We receive Christ for our salvation, and then we are predestinated to be his children. It has nothing to do with salvation.
Romans 8:28-29: “And we know that all things work together for good to them that love God, to them who are the called according to his purpose. For whom he did foreknow, he also did predestinate to be conformed to the image of his Son, that he might be the firstborn among many brethren.”
Look at Romans 8:28-29 and notice that it is not saying predestination in receiving Jesus Christ for salvation. It says predestination to be confirmed in the image of his Son.