Jesus
Did Jesus die for everyone?
This connects directly to the predestination debate discussed elsewhere, sometimes summarized as "limited" versus "unlimited" atonement—genuinely, actively disputed among sincere, Bible-committed Christians.
Reformed and Calvinist Christians generally hold "limited" or "particular" atonement: Christ's death specifically secures salvation for the elect, though many in this tradition also affirm the cross is sufficient "for all" even while its saving intent was particular. Arminian and many other Christians hold "unlimited" or "general" atonement: Christ died for every person without exception, though only those who respond in faith receive its saving benefit.
Key texts get read differently by each side: "God so loved the world" and "not for ours only but also for the whole world" support the general view, while "he will save his people from their sins" and the Good Shepherd laying down his life "for the sheep" support the particular view. Both sides affirm salvation is entirely by grace through faith, disagreeing only about the intended scope of Christ's death.
Bible quotations in these answers are generally taken from the Christian Standard Bible®, Copyright © 2017 by Holman Bible Publishers. Used by permission. Christian Standard Bible® and CSB® are federally registered trademarks of Holman Bible Publishers. Some biblical wording may be paraphrased or follow other translations.