"What does faith in Christ entail?"
Perhaps the famous question posed to Peter in the second chapter of Acts can help us sort that question out. After Peter told the crowd they were responsible for crucifying Jesus, they asked Peter and the other apostles, "Brothers, what shall we do?" And Peter replied, "Repent and be baptized, every one of you, in the name of Jesus Christ for the forgiveness of your sins. And you will receive the gift of the Holy Spirit."
Ah, so here's a clear directive: having faith in Christ requires repenting and being baptized whereupon one receives the gift of the Holy Spirit: lempsesthe ten dorean tou agiou pneumatos. As Jesus himself instructed the disciples, "Make all nations disciples, baptizing them in the Name of the Father and of the Son and of the Holy Spirit." So, it's clear that faith in Christ means you have to be baptized and receive the Holy Spirit.
But what about repenting?
"To repent" is a translation of metanoia, that is, to "change your mind." That raises a question: From what do we change our minds and to what should our minds be oriented? That's pretty simple: From the values of this world to the values of the Kingdom of God, where the last are first, and the first are last, and the poor are provided for, and the sick are healed; where cheeks are turned and enemies are forgiven and domination submits to love. So "being saved" means exiting the world of power and violence and entering the Kingdom of God, or least striving to enter the Kingdom of God, while leaving behind the jealousy, rivalry, and selfishness of earthly kingdoms.
Jesus says as much in his parable of the sheep and the goats in Matthew 25:31-46:
31 "When the Son of Man comes in his glory, and all the angels with him, he will sit on his glorious throne. 32 All the nations will be gathered before him, and he will separate the people one from another as a shepherd separates the sheep from the goats. 33 He will put the sheep on his right and the goats on his left.
34 "Then the King will say to those on his right, 'Come, you who are blessed by my Father; take your inheritance, the kingdom prepared for you since the creation of the world. 35 For I was hungry and you gave me something to eat, I was thirsty and you gave me something to drink, I was a stranger and you invited me in, 36 I needed clothes and you clothed me, I was sick and you looked after me, I was in prison and you came to visit me.'
37 "Then the righteous will answer him, 'Lord, when did we see you hungry and feed you, or thirsty and give you something to drink? 38 When did we see you a stranger and invite you in, or needing clothes and clothe you? 39 When did we see you sick or in prison and go to visit you?'
40 "The King will reply, 'Truly I tell you, whatever you did for one of the least of these brothers and sisters of mine, you did for me.'
41 "Then he will say to those on his left, 'Depart from me, you who are cursed, into the eternal fire prepared for the devil and his angels. 42 For I was hungry and you gave me nothing to eat, I was thirsty and you gave me nothing to drink, 43 I was a stranger and you did not invite me in, I needed clothes and you did not clothe me, I was sick and in prison and you did not look after me.'
44 "They also will answer, 'Lord, when did we see you hungry or thirsty or a stranger or needing clothes or sick or in prison, and did not help you?'
45 "He will reply, 'Truly I tell you, whatever you did not do for one of the least of these, you did not do for me.'
46 "Then they will go away to eternal punishment, but the righteous to eternal life."
Now we're getting somewhere. Our eternal destiny depends on how we treat other people, especially those people who cannot benefit us in any way. The folks who were sent into the eternal fire were not damned because of their faith but because they didn't take care of others.
You may wonder how I can deny the existence of Hell—eternal conscious torment—when it seems so clearly attested in the above parable.
Three reasons:
First, when Jesus was on the cross, he said, "Father, forgive them for they not what they do." His forgiveness includes the Roman soldiers, the Sanhedrin, the disciples who fled, and the mob that cried out for his crucifixion. If those who droves the nails are forgiven, then so are the selfish folks who don't help their neighbors.
Second, I can't persuade myself that being burned alive forever is just. It's too much, and if God really does burn people alive forever, then we are all screwed, regardless of what we believe.
Trust me on this one. If you believe you are saved by faith alone, you will find on the Day of Judgment that works are necessary. If you believe that works collaborate with grace, then you'll find that you are damned because you didn't believe that you were saved by grace alone. If you claim Christ alone, you will hear that you didn't follow him correctly.
A God who creates an eternal hell to torture people who have been deceived by appearances at every turn, propagandized by governments and manipulated by advertisers, betrayed by hypocritical Christian leaders claiming the truth, confused by competing doctrines, and burdened with a reason that will not permit them to believe what they perceive as irrational, a people who, moreover, have suffered terrible losses—as we all do, for we and everyone we love will die—and therefore paid more than enough in mourning, illness, and agony for the unrequested existence we endure, I say, a Deity that would torture forever his own miserable creation is insatiable in his lust for domination and punishment, and we—regardless of what we believe—are profoundly and irredeemably screwed.
Third reason, I am a thoroughgoing Girardian who interprets the flames of Hell as a world consumed by mimetic desire from which we can escape only by following the example of Christ. As Girard writes in Things Hidden from the Foundation of the World, "to follow Christ is to walk away from mimetic desire."
What is mimetic desire, you ask?
Put two kids in a room full of toys. One kid picks up a toy. What does the other kid want? He wants that toy. There are hundreds of toys, but that's the only toy he wants. Why? Because his desire for the toy has nothing to do with the toy itself but only because the first kid possesses it.
Girard argues that basic desires for food and water aside, all desire is motivated and exacerbated by this kind of imitated (or mimetic) desire. The real focus of the "second kid" who wants the toy is not the toy at all, but the first kid who possesses it, and the "first kid" inevitably becomes his rival, the source of the "second kid's" desire and the obstacle to fulfilling his desire.
What happens?
Probably a fight, but the "first kid" may be submissive and give the toy up. Either way, what begins as the mimetic desire for an object inevitably leads to a desire to dominate.
So, how does mimetic desire equate to Hell?
Just look around: Our world of domination and submission is hell. Masters and slaves, victors and victims, bullies and bullied. A person who refuses to give a cup of water to someone who is thirsty is not only in hell, but he or she is creating hell. They are so selfish they can't relinquish a sip of what they have. Domination is such a person's God.
But that is not a good world, and Nietzsche is full of shit.
Mimetic desire is the motive force underlying the nuclear rivalry between nations. That is, one nation has a Bomb, so other nations desire a Bomb but even more powerful and destructive bombs than the original bomb. The rivalry keeps ramping up until we live a world with thousands of Bombs, and we find ourselves tottering at the lip of a radioactive conflagration. The only "doctrine" that prevents us from nuclear annihilation is MAD, Mutually Assured Destruction.
When we finally tip over into the abyss, we will experience the Fall of Man once and for all.
And that Fall will be into Hell. The only belief that can save humankind is a belief in the Kingdom of God as Christ taught it. The Kingdom of God is the only alternative to mimetic desire—and Hell.