There are three sets of scriptures that one has to account for in dealing with this issue.
1) Scriptures apparently asserting the absolute sovereignty of God.
2) Scriptures apparently indicating God's universal love and universal intent to save.
3) Scriptures apparently indicating that Satan, and many humans, are punished eternally for their sins.
I say apparently because the "apparent" implications of one set of passages has to be only apparent. You have to deny the apparent implications of one of these sets. And Christian Bible interpreters have alternative interpretations for each of these sets. You can say that the sovereignty passages do not mean to imply that God doesn't permit humans to choose freely. You can say that the universal intent to save passages have implicit in them a limited reference class that limits the scope of God's love and/or the intended benefit of God's salvific actions to the elect. (Actually, Calvinists are split on whether God loves everyone, even those that God reprobates.) And, interestingly enough, there are Christians who have argued that "eternal" punishment for the wicked is only age-long, not forever, and is designed to bring about an eventual redemption, which means that eventually everyone will be saved. In the first four centuries of the church, universalism was far more prevalent that what later became known as Calvinism.
Or, of course, you can say that, based on Scripture, we are not in a position to extrapolate and decide what the correct answer to this issue is.
And just in case someone gets the wrong idea, there is nothing in here intended to attack Calvinism.