When we understand that Christs Death actually converts them He died for to God, its easy to understand He didnt merely die for all without exception, in which all without exception are converted to God. His Death brings us to God 1 Pet 3:18

For Christ also hath once suffered for sins, the just for the unjust, that he might bring us to God, being put to death in the flesh, but quickened by the Spirit:

That word bring is greek word prosagō:

to lead, to bring

to open a way of access, for one to God

to render one acceptable to God

in a forensic sense, to summon (to trial or punishment)

to draw near to, approach

the land which a sailor is approaching seeming to approach him

Psalms 65:4

Blessed is the man whom thou choosest,
and causest to approach unto thee, that he may dwell in thy courts: