Actually, it's
Revelation 21:8 that states, "But the fearful, and
unbelieving, and the abominable, and murderers, and whoremongers, and sorcerers, and idolaters, and all liars, shall have their part in the lake which burneth with fire and brimstone: which is the second death."
With that, if the prodigal son wouldn't have returned to the father because he didn't think he needed to in order to receive his reward (unbelieving, specifically without Christian faith), wouldn't he be counted among those who found their part in the lake of fire?
I'm also slightly confused with your comment - Are you saying,
A) The Spirit and bride are saying, "Come!", to people now in order to come to the Father
or
B) The Spirit and bride are saying, "Come!", to the people who are outside the Holy City described in 21:8
or
C) The Spirit and bride are saying, "Come!", to the people who are prodigal sons/daughters in reality
or
D) Something different?