being justified as a gift by His grace through the redemption which is in Christ Jesus;
In Christ we have justification given to us as a gift. You do not earn a gift you simply receive it. Justified means you have been “Declared Righteous” (right with God), and because you have been declared right with God you have been redeemed from the curse of the law and given the blessing of Abraham. Jesus purchased this gift for you. You don’t try to get right with God you already are because of what Christ has done for you. It is because of justification you now have the right to all that Christ has provided for you.
We don’t receive what Christ has provided for us because we have earned it, but because we have been made right with God. So just as you receive salvation by faith in what Jesus Christ has done for you to be made right with God, so do you also by faith in Him receive all that He has provided for us in the New Covenant. For all who are born again have been made the righteousness of God, and through your right standing with Him you receive what God has for you by faith in what Christ has done for you.