The Christian should fear it.
But the Christian should fear it for the correct reason.
And I believe there are only two reasons to fear Hell.
The first of the two reasons to fear Hell is for the torture of Hell. I won’t quote the Scripture’s ghastly depictions of Hell. We know them well. Weeping. Wailing. Unquenchable fire. Hell is terribly miserable, a painful punishment of both physical and psychological proportions. And it is eternal. That’s scary. It is a reason to fear Hell. But it should not be the Christian’s reason for fearing Hell.
The second and most pure reason is for what is lost in Hell: friendship with God. We shouldn’t be fearful for what is given to us in Hell, but in what we have lost in finding ourselves there. Hell is eternal separation from God. It is an eternal failure to fulfill our intended design. It is an eternity of heartbreak because it is an eternity without the love for which our hearts were created. This knowledge should instill in us a deep fear. Not the kind of fear that the woman in the movie, running with the 5-inch heels from the masked man with a chainsaw experiences, but a sort of fear that one might experience when they have disappointed a friend (if that makes sense).
When we consider our sins and our failures and confess them in prayer and in the Sacrament of Reconciliation, we need to beg God for the second fear, a fear that is motivated from love, and not from, well, fear. It’s ok to express sorrow for our sins in both ways, being afraid of both hellfire and eternal separation from God, but we should be striving to more and more express sorrow out love and not out of fear of punishment.