Why a belief in hell is so practically important

We don’t believe in hell for practical reasons.  We believe in it because the Bible tells us it is so, and that settles it for us.  No matter what some may say, we cannot be shaken from that.  But, I ask, do we really live in light of that belief?  Is is something that emotionally impacts us?  Do we feel it’s truth?  If not, as Piper points out, we will both be complacent about our friends and neighbours and lacking in passion in our gratitude to Jesus for what he has done for us:

BROTHERS, WE MUST FEEL THE TRUTH OF HELL
IS NOT OUR most painful failure in the pastorate the inability to weep over the unbelievers in our neighborhoods and the carnal members of our churches? A great hindrance to our ministry is the gulf between our Biblical understanding and the corresponding passions of our hearts. The glorious and horrible truths which thunder through the Bible cause only a faint echo of fear and ecstasy in our hearts. We take a megaton of truth upon our lips and speak it with an ounce of passion. Do we believe in our hearts what we espouse with our lips?
I know for myself that in order to be a true shepherd and not a hireling, in order to grieve over the straying lambs, and in order to summon with tears the wild goats, I must believe in my heart certain terrible and wonderful things. If I am to love with the meek, humble, tender, self-effacing heart of Christ, I must feel the awful and glorious truths of Scripture. Specifically:
•      I must feel the truth of hell—that it exists and is terrible and horrible beyond imaginings forever and ever. “These will go away into eternal punishment” (Matt. 25:46) . . .
•     I must feel the truth that once I was as close to hell as I am to the chair I am sitting on—even closer. Its darkness, like vapor, had entered my soul and was luring me down. Its heat had already seared the skin of my conscience. Its views were my views. I was a son of hell (Matt. 23:15), a child of the Devil (John 8:44) and of wrath (Eph. 2:3). I belonged to the viper’s brood (Matt. 3:7), without hope and without God (Eph. 2:12). I must believe that just as a rock climber, having slipped, hangs over the deadly cliff by his fingertips, so I once hung over hell and was a heartbeat away from eternal torment. I say it slowly, eternal torment!
. . . If I do not believe in my heart these awful truths—believe them so that they are real in my feelings—then the blessed love of God in Christ will scarcely shine at all. The sweetness of the air of redemption will be hardly detectable. The infinite marvel of my new life will be commonplace. The wonder that to me, a child of hell, all things are given for an inheritance will not strike me speechless with trembling humility and lowly gratitude.
John Piper, Brothers, We Are Not Professionals : A Plea to Pastors for Radical Ministry (Nashville, Tenn.: Broadman & Holman Publishers, 2002), 115-16.John Piper, Brothers, We Are Not Professionals : A Plea to Pastors for Radical Ministry (Nashville, Tenn.: Broadman & Holman Publishers, 2002), 113-15.

Adrian Warnock