Article II — That, agreeably thereto, Jesus Christ, the Savior of the world, died for all men and for every man, so that he has obtained for them all, by his death on the cross, redemption, and the forgiveness of sins; yet that no one actually enjoys this forgiveness of sins, except the believer, according to the word of the Gospel of John iii. 16: “God so loved the world that he gave his only-begotten Son, that whosoever believeth in him should not perish, but have everlasting life”; and in the First Epistle of John ii. 2: “And he is the propitiation for our sins; and not for ours only, but also for the sins of the whole world.”

Piper: “The atonement of Christ is sufficient for all humans and effective for those who trust him. It is not limited in its worth or sufficiency to save all who believe. But the full, saving effectiveness of the atonement that Jesus accomplished is limited to those for whom that saving effect was prepared. The availability of the total sufficiency of the atonement is for all people. Whosoever will—whoever believes—will be covered by the blood of Christ.”

My question, then, is simply: how are these different?