You keep saying this and I'm not sure why. Yes, God has designed human interaction into His plan of salvation, tis why we have preachers and teachers. Faith cometh by hearing and hearing by the Word of God - human interaction - it takes preachers and hearers.
there is no human interaction in relation to ETERNAL salvation/redemption. All action is on the part of God. He electED, He redeemED. check out Romans 8:28-30.
Human interaction (faith cometh by hearing, and hearing by the word of God, preachers, hearers, obedience, disobedience, blessing, cursing, etc., etc., ) is in relation to TIME or GOSPEL salvation, should God's timely plan for the individual is to be a member of a flock here in time.
Did God command Moses to take the law as well to the heathen around Israel, or was He ordered to expound the law and enforce it only among Israel and whoever stranger sojourns with them ?
what was it Paul said in Romans 15:4 ? for whom was everything that was written, written ? and in 1 Corinthians 10:12 (?) ? what happened to whom happened as an example to whom ?
the redemption of the human soul is purely God's prerogative, and He did it well.
man's problem has always been that he wants himself in the equation.