Timothy 4:10 says:
For to this end we toil and strive, because we have our hope set on the living God, who is the Savior of all people, especially of those who believe.
True Christ died and paid the price of sin for the whole world, so while that is universal, the added part of that verse, “especially of those who believe”, let's us know who specifically it applies to.
Perhaps the word “all”, is what is throwing you off. The Greek word used is “pas”, meaning in this verse “many types or kind”.
God is everyone's Savior for those who accept that offer. sadly not all (or many) do or will.