For everyone who is interested in the truth. Let's look at the whole picture...
God created the entire world. Everything that exists in it, including humans, was created by God. However, humans went astray right at the beginning, when Adam and Eve disobeyed God. They were the first to sin, and sin was thereby passed on to their progeny, i.e., everyone. God, being just, had to punish Adam and Eve and their progeny. He did this through sacrifice.
In the Old Testament, sins were paid for by substitutionary sacrifice. Rather than God insisting that a person be sacrificed for their sins, God permitted a substitute. Under the old covenant, this sacrifice was in the form of an animal: a sheep or a goat or a bull or a dove. Regardless, a life had to be sacrificed to atone (pay for) the sins committed.
In the New Testament, God created one final sacrifice for sins: His own Son! This sacrifice paid the sins for all people!!! (Please read that sentence again!) The sacrifice of Jesus Christ satisfied God's requirement that sin must be paid for -- a life for a life.
Now to whom does that sacrifice apply? TO EVERYONE!!! There is not one single person to whom that does not apply!
However, as has always been the case, the person must accept the fact that the sacrifice is a substitute for themselves and applies to her/him personally. If a person does not agree that the sacrifice is a substitution for her/his punishment, then the sacrifice is of no effect.
JESUS' SACRIFICE WAS MADE ON BEHALF OF ALL PEOPLE!!! THERE IS NOT A SINGLE PERSON TO WHOM IT DOESN'T APPLY. However, each person must accept the fact that the sacrifice of Jesus was done for them personally. If s/he doesn't accept that fact, then they will be punished for their sin(s).
It isn't any more complicated than that. Anyone who tells you that Jesus' sacrifice doesn't apply to all people is either deliberately lying or doesn't understand the truth that is so clearly stated in the Bible.