So God has not spoken to us by his Son?
Were the "us" being spoken to of THEIR Fenway Park, and of THEIR New England Clam Chowder, etc., it'd be easy to determine that people from Massachusetts were being addressed, and about THEIR things.
What does Hebrews continually go on about to its' "us" - THEIR Law and THEIR Prophets, and THEIR Priesthood, and so on...
And ALL OF IT as if addressing THE HEBREWS.
Hebrews 1:1 God, who at sundry times and in divers manners spake in time past unto the fathers by the prophets, 1:2 Hath in these last days spoken unto us by his Son, whom he hath appointed heir of all things, by whom also he made the worlds;
Hebrews 2:16 For verily he took not on him the nature of angels; but he took on him the seed of Abraham. 2:17 Wherefore in all things it behoved him to be made like unto his brethren, that he might be a merciful and faithful high priest in things pertaining to God, to make reconciliation for the sins of the people.
REPEATEDLY and THROUGHOUT Scripture, the phrase "the people" VERY often refers to THE HEBREW PEOPLE.
Acts 3:12 And when Peter saw it, he answered unto the people, Ye men of Israel, why marvel ye at this? or why look ye so earnestly on us, as though by our own power or holiness we had made this man to walk?
Acts 4:1 And as they spake unto the people, the priests, and the captain of the temple, and the Sadducees, came upon them,
Acts 4:8 Then Peter, filled with the Holy Ghost, said unto them, Ye rulers of the people, and elders of Israel,
Acts 4:10 Be it known unto you all, and to all the people of Israel, that by the name of Jesus Christ of Nazareth, whom ye crucified, whom God raised from the dead, even by him doth this man stand here before you whole.
Acts 4:27 For of a truth against thy holy child Jesus, whom thou hast anointed, both Herod, and Pontius Pilate, with the Gentiles, and the people of Israel, were gathered together,
Must be why the book of HEBREWS is referred to as "the Epistle to THE HEBREWS."
Only some previously acquired bias or another, going in, would conclude otherwise.
Nevertheless, Romans 5:6-8 towards ya.