One Decree of God, Not Many - COD 1:7-8

ARTICLE 7
Election is the unchangeable purpose of God, whereby, before the foundation of the world, He has out of mere grace, according to the sovereign good pleasure of His own will, chosen from the whole human race, which had fallen through their own fault from their primitive state of rectitude into sin and destruction, a certain number of persons to redemption in Christ, whom He from eternity appointed the Mediator and Head of the elect and the foundation of salvation. This elect number, though by nature neither better nor more deserving than others, but with them involved in one common misery, God has decreed to give to Christ to be saved by Him, and effectually to call and draw them to His communion by His Word and Spirit; to bestow upon them true faith, justification, and sanctification; and having powerfully preserved them in the fellowship of His Son, finally to glorify them for the demonstration of His mercy, and for the praise of the riches of His glorious grace; as it is written: Just as He chose us in Him before the foundation of the world, that we should be holy and without blame before Him in love, having predestined us to adoption as sons by Jesus Christ to Himself, according to the good pleasure of His will, to the praise of the glory of His grace, by which He has made us accepted in the Beloved (Eph. 1:4–6). And elsewhere, Whom He predestined, these He also called; whom He called, these He also justified; and whom He justified, these He also glorified (Rom. 8:30).
ARTICLE 8
There are not various decrees of election, but one and the same decree respecting all those who shall be saved, both under the Old and the New Testament; since the Scripture declares