Abiding in the Master of Reconciliiation is a present tense operation of Spirit. The purpose of that union with Him is more of Him (and less of you/us). Each individual as a wee will can dig in their wee feet and say no. In the end however, the Master accomplishes His will in every digit, of every life, to whom the Father gives Him.
"These are they who follow the Lamb withersoever He goes."
Verse 6 doesn’t sound like they’re being forced to abide. Are you familiar with the term “cast away” (ballō G906)
1. to throw or let go of a thing
without caring where it falls
a. to scatter, to throw, cast into
b. to give over to one's care
uncertain about the result
c. of fluids
1. to pour, pour into of rivers
2. to pour out
2. to put into, insert
A primary verb; to throw (in various applications,
more or less violent or intense): - arise, cast (out), X dung, lay, lie, pour, put (up), send, strike, throw (down), thrust. Compare
God does not need man. He will accept those who turn to Him but those who reject Him, He will cast away. I’m curious where you got this idea from when you said “The purpose of that union with Him is more of Him (and less of you/us).” It’s a synergetic relationship that requires the acceptance of both parties. Sure God is loving, patient, and long suffering but He is also jealous, vengeful, and just. He will give everyone every opportunity to repent but if they choose not to then He will abandon them to their fate.
“And He began telling this parable: "A man had a fig tree which had been planted in his vineyard; and he came looking for fruit on it and did not find any. And he said to the vineyard-keeper, 'Behold, for three years I have come looking for fruit on this fig tree without finding any. Cut it down! Why does it even use up the ground?' And he answered and said to him, 'Let it alone, sir, for this year too, until I dig around it and put in fertilizer; and if it bears fruit next year, fine; but if not, cut it down.'"”
Luke 13:6-9 NASB
Notice in this example the vineyard owner (God The Father) doesn’t have an infinite amount of patience towards the fig tree (man). There is a cut off point to where God will eventually abandon a person to their fate. God urges people to repent He does not force it. God does not use the lake of fire to force repentance.