Q: If a person’s transgressions are unforgiven, how can a person be saved?

A: This is during Jesus earthly ministry to His own people,  preaching about Israel’s hope, the kingdom to come on earth. To be unforgiven, in this sense, the person (persons) will not be resurrected to be in the millennial kingdom. 

But, that doesn’t mean he won’t be conciliated with the whole universe at the end of the eons.