Perhaps what you missed is the dialectic in Barth's theology, Torrance's too for that matter. Atonement is not just sufficient for all and efficacious for some (by faith); it is complete, effective, and universal in scope. Nothing can separate humanity ~ via our inclusive election in Christ ~ from the love of God that is in Christ Jesus our Lord. This is the "objective" pole of salvation. The "subjective" pole is the active response of believers by way of faith participation in and through Jesus Christ.
The question of course regards those who hang in the balance, they being three groups: those who are incapable of "belief" ~ infants, etc; those who have not heard the true Gospel message, thus having had no opportunity to respond; and those who have heard, do understand, and still reject Jesus Christ. This latter group are likely destined to face the second death alone. The former group are raised from the dead safely in the arms of Jesus. The group in the middle are those with whom we seek to reach with the Good News of Jesus Christ. Because it is truly good news and the power of God into (eis) salvation, they are likely to believe and benefit immediately from the surety of Christ's Spirit in them, the sanctifying hope of glory.
The dialectic is the tension between the two poles. Where do we concentrate our preaching/teaching: on the Good News of humanity's full and effective inclusion in Christ's atoning work or on humanity's call to participate in it by faith? In no respect does faith "activate" salvation. Barth thought the former; Torrance the same. "Therefore repent and believe the good news" comes at the end of Gospel, in full awareness of their inclusion in it, and not set as a condition upon receiving it. Those who believe receive the gift of the Holy Spirit, the surety of their salvation. Those who don't, we leave to the righteous, just, and merciful (all contained in the meaning of one word in Hebrew) judgment of God in Christ. It is not our call to make; hence the tension.
From my take on your understanding of Hunsinger, you may have missed the efficacy of the objective pole ~ that all truly does mean all ~ thus (still) throwing the entire weight of salvation on the backs of respondents, that being their obligation to believe in order to receive. Or from the other Federal Calvinist side, making God the bad guy for electing only some to salvation (I know, I know; it's really our fault).
Thoughts?
the good news being the (empowerment/grace) through (His) work
and the encouragement to repent, believe and receive.
It's always God's call to make and He, not our doctrines on the judgement day judges. He is the door.
there is obviously those that deny and thus 2nd death is applicable.
grace/empowerment makes responding capable.
preaching the gospel is thus still a valid need and command to bring the message to those so they (the lost) can access the empowerment to believe and give assurance and involvement with the body (before) judgement.
the commands to
preach the gospel
be a light and ((let)) your light shine
be in fellowship thus letting the lost see the love we have for one another.
we become co laborers with christ in a reconciliation ministry.
all of the above gives the tension and responsibility of the believers
to partner with Christs work The (gospel)
thus Christ does the work forgiving all of sin.
sends the Holy Spirit to empower US to (fully preach) the gospel.
Thus allowing/enabling the lost to activate the grace.
God desires that all should (come) to repentance. no need for coming or repenting if hyper calvinism is true.
the above punctuates all the scriptures that encourage the (church) to preach and display the Gospel and his love.
to reach that middle group who have not heard and if never hear will be judged with His mercy. not ours.
gospel tension is
Christs work
churches commissions and mandates to bring that good news
so that
Gods desire that (all) would (come) to (repent) and yet some will still (deny)
All have the potential to be saved. some will deny.