Gosh, they could be angels, non believing Jews, any Christian...? Possibly they are interchangeable terms? "Sons of God/Son's of the Kingdom"...some translations say "children of the Kingdom". Very confusing and leaves too much room for error IMHO. So yeah, on the shelf
Matthew 8:10-13 KJV
10) When Jesus heard it, he marvelled, and said to them that followed, Verily I say unto you, I have not found so great faith, no, not in Israel.
11) And I say unto you,
That many shall come from the east and west, and shall sit down with Abraham, and Isaac, and Jacob, in the kingdom of heaven.
12) But the children of the kingdom shall be cast out into outer darkness: there shall be weeping and gnashing of teeth.
13) And Jesus said unto the centurion, Go thy way; and as thou hast believed, so be it done unto thee. And his servant was healed in the selfsame hour.
I find "east and west" were used when the location is the earth.
Luke 13:23-30 KJV
23) Then said one unto him, Lord, are there few that be saved? And he said unto them,
24) Strive to enter in at the strait gate: for many, I say unto you, will seek to enter in, and shall not be able.
25) When once the master of the house is risen up, and hath shut to the door, and ye begin to stand without, and to knock at the door, saying, Lord, Lord, open unto us; and he shall answer and say unto you, I know you not whence ye are:
26) Then shall ye begin to say, We have eaten and drunk in thy presence, and thou hast taught in our streets.
27) But he shall say, I tell you, I know you not whence ye are; depart from me, all ye workers of iniquity.
28) There shall be weeping and gnashing of teeth, when ye shall see Abraham, and Isaac, and Jacob, and all the prophets, in the kingdom of God, and you yourselves thrust out.
29) And they shall come from the east, and from the west, and from the north, and from the south, and shall sit down in the kingdom of God.
30) And, behold, there are last which shall be first, and there are first which shall be last.
Much love!