"Gather to me my consecrated ones,
who made a covenant with me by sacrifice."
These are His words as He summons the earth.
Being in the Old Testament, the words, "covenant with me by sacrifice" are important words. These signify that God is talking about His people, the children of Israel. They are His people because on at least some outward level they have made a profession of faith. They have followed in obedience by making a covenant with God and by offering their sacrifices to Him.
If this is real and genuine, then they are the consecrated ones. They are the ones who are set apart for His use.
Times are different now. The one true sacrifice has been made, but the idea is still the same. True faith in Him, in His sacrifice, and you will be in the crowd of the consecrated ones.