The death of jesus was sufficient to allow God to save all sinners, but he intended it to only save some sinners, as this passage refers to His death fior the many, and not for the all!
What I am saying is that there is Calvinism and then there is Calvinism. There is a simplistic version (not in a good way) that distills down certain truths (or certain conclusions) and uses this to build an entire “theology”.
It goes like this:
Man has sinned against God and God’s justice demands that He punish every sin. So God chooses a people (the elect) offers His Son on the Cross and punishes Him with the wrath that was due those sinful acts of the elect, effectively atoning for those sins (the debt is paid) and making God both Just and the Justifier of sinners. Those who are non-elect do not have their sins atoned for because Jesus’ punishment (although sufficient because Jesus’ worth as God surpasses the sins of all mankind) did not include the punishment for their sins. At Judgment, the Father will look on the elect as if they were Christ (the payment already rendered) and will pour out His wrath on those who are not chosen (those who do not believe).
I’m not accusing you of this position, but I do see you as sometimes going off in that direction and I am trying to pull you back into Scripture (which is why I often ask for a passage in reference). Scripture does not present God’s wrath against sin as God’s wrath against a sinful act but as God’s judgment against sinners. The example above misunderstands both the nature of sin and the nature of judgment. No one can be punished for my individual sins except me (what I need is forgiveness, not a substitute in this context). Scripture teaches that Christ became man and took on the consequences of sin for mankind in such a way that God will judge the world through Christ (Acts 10:42). And indeed the Father does not judge anyone but has given all judgment to the Son (John 5:22).
So you see how that simplistic, watered down, man-centered (elect centered) version of Calvinism (if we would still call it that) can be a very dangerous thing. It’s so narrow that it forms a tight doctrine where everything is interdependent (remove one thing and the whole thing crumbles) but it is also very much philosophical ideas and very little Scripture (in fact, it denies much of Scripture).
And again - I am not saying this is Calvinism (or that this is what you believe) but it is how some present the position (on both sides). And it is wrong.