God has always had a people. From ancient times until now, God's people have been the people of faith -- people who trust God to keep His promises. These are those who always rely on God's provision and seek His eternal kingdom.

But since the fall, Satan has had his people too. These are those who don't trust in God or His promises. They take matters in their own hands and live only for this world.

For we have become partakers of Christ, if we hold fast the beginning of our assurance firm until the end ... Therefore, let us fear if, while a promise remains of entering His rest, any one of you may seem to have come short of it. For indeed we have had good news preached to us, just as they also; but the word they heard did not profit them, because it was not united by faith in those who heard (Hebrews 3:14, 4:1-2 New American Standard Bible).

Friends, it's that simple.