None teach "works alone". And even those that teach "faith alone", don't mean by that idea that works are not important. It all has to do with the word "needed". Needed for what?
It is the reformed group of protestant churches (Lutheran, Presbyterian, Baptist and others) that teach a collection of doctrines sometimes grouped together and called the Five Solas (from the Latin phrase that introduces each concept):
Sola scriptura ("by Scripture alone")
Sola fide ("by faith alone")
Sola gratia ("by grace alone")
Solus Christus or Solo Christo ("Christ alone" or "through Christ alone")
Soli Deo gloria ("glory to God alone")
People, even members of those denominations, often get confused and think that sola fide and sola gratia are the same thing. They are not. And that is why the question, "Needed for what?", is so important.
When it comes to salvation, it is neither faith only nor work only that is taught by any Christian denomination. What saves us is not what we do nor what we believe, but God's will experienced as an act of grace or mercy. Christians, of all stripes, do not believe that they are ever in their natural state worthy of being saved. Nor do we believe that we could ever do or believe something that would make God owe us salvation. So, if you are talking about what is needed to get into heaven, faith or works? The answer is actually neither will do you any good. Because, unless God is willing to grant you heaven as a gift, you can believe what you want and do all of the good works possible, and God still does not have to let you in. Ultimately we get in by grace alone.
One of the main biblical texts for this understanding is Ephesians 2:8-9 -- "For it is by grace you have been saved, through faith—and this not from yourselves, it is the gift of God— not by works, so that no one can boast."
Now, as I said, some people get confused and think that this means that we are saved through faith alone and not by works. But note, that is NOT what is actually said. Rather we are save by grace. And though we are not saved by works, the next sentence makes it clear just how important they are as well: "For we are God's workmanship, created in Christ Jesus to do good works, which God prepared in advance for us to do" (Ephesians 2:10). So, all Christians understand that it is important to do good works, it is just that works alone do not save us. Rather, the only thing that saves us is God's grace. And how do we experience God's grace? Well, until we are actually in heaven it is just the hope of something longed for. Still, because we trust not in our own work, but in the work that we understand that Christ has done, we are certain of it even as it remains unseen. And this just happens to be the way that the Bible speaks of faith: "Now faith is being sure of what we hope for and certain of what we do not see" (Hebrews 11:1). And I expect that this is why Paul spoke of being saved by grace through faith. If one didn't trust in Jesus, one might still be saved by God's grace, but one would not have knowledge of it unless they had faith that they could trust in what God did before we actually had the experience of it.
So, what do people mean when they speak of Sola fide ("by faith alone")? Sola fide is the teaching that justification (interpreted in Protestant theology as, "being declared right by God") is received by faith only, without any mixture of or need for good works. (Remember I said in my post on the last page that these were all important words to understanding this discussion -- you may want to look them up again.)
In Islamic tradition there is a tradition that on arriving in heaven one's works are weighed. And yet that same tradition says that no one can enter paradise based on their works, for always they are found wanting. In the end, it is Allah alone who decides and grants permission. That act of granting permission is what we mean by grace alone. But the fact that a Muslim can live confident that Allah is going to grant that grace is what we mean by "faith alone". You know that Allah is going to look at your works and decide that, even though they don't measure up to the point that Allah would have to declare you righteous -- because reality is that you will never be as righteous as Allah, that Allah is going to declare them acceptable (that declaration that Allah finds your life acceptable or righteous is what we mean by justification). That reason is not so much the content of your works (though of course they are righteous works), but the dedication of your heart to living a life of Islam, submission to Allah.
So, in a way very similar to Christian understanding, Muslims also receive grace (from Allah) through faith (your trust in the nature of Allah's final decision). And because you live by faith today trusting in the ultimate goodness and mercy of Allah, you also respond by submitting to Allah's will and do the works that he would ask of you, as if they will be good enough.
Now, Catholic Christians don't disagree with Protestants over the idea of grace alone, but they do think that justification is a result of more than just faith alone. And here Islam might be more like Catholic ideas than Protestant ideas. For Catholics would suggest that faith alone is not good enough to show that one really loves God. And God is not looking just for people who believe in him, but for people who are willing to trust AND obey. Particularly to obey his command to love -- love both of God and love of others. Catholics (and really most protestants too) say that this love is expressed in and by our works.
This is what the the author of the letter of James is talking about. He says that if a person doesn't have works, then he questions whether or not they really have faith. For faith without works isn't really faith at all. If we are saved by [God's] grace through faith, James says that this faith must be alive. (Paul also talks about the importance of having living faith, so this is really not a different teaching.) And he says that living faith is not something that you keep hidden inside by just thinking about God. (Remember I said that faith was not just an intellectual pursuit on the previous page.) Real faith must be put to action. And when it involves trusting God, it will mean trusting him to tell us how to live as well. That means we need to pay attention to the commands of Christ, and Jesus made it plain that he was giving us a new commandment: "A new command I give you: Love one another. As I have loved you, so you must love one another" (John 13:34). So, all that James is doing in his letter is holding those who say that they believe in Jesus, that God is going to say that Jesus' work (not ours) is sufficient to save us, had better be living like they really trust and believe in Jesus. And that means more than just lip service, but actually acting on that faith and to begin doing the things that Jesus said. Thus if we have faith, James expects to see the fruit of that faith. We are to love and show love -- feed the hungry, clothe the naked, give shelter to the homeless, care for the sick and visit the imprisoned.
Now, believe it or not, what I have written is just for starters (and why I was going to wait till next week to address your question). But I think I had better stop for the moment and see what I might have answered. What I've actually made more confusing. And what maybe I haven't addressed at all.
