Is it the dead religion? Absolutely not. I come from the country where lots and lots of people are extremely devoted to Roman Catholic Church, especially young people. They study The Bible, are parts of Christian associations and live accordingly by The Church rules. It is clear for me that this is important to them.
But will it die in the future? It might. As I perceive those people I feel there is something... reactionary in their devotion. I live in a conservative country and the narration of mainstream media is very xenophobic. People are scared of many trends that come to us from Western Europe; they are scared of LGBT movement, of gender and sexual orientation-confusion and drama regarding it, they are scared by the existential crisis that comes from having too many options in life and having to decide how to live your life all by yourself, without any clear guidelines. They stick to religion because it seems familiar and therefore reassuring. It makes the world simpler as it deems some options as immoral and reduces the uncertainty.
I think they need faith, because it lies within majority of people's needs to have faith. I grew up in atheistic/agnostic family and it was generating much anxiety for me even though the need to believe in something wasn't transmitted onto me from other people, so I think that at least some of us has the inborn need for faith. We do have such needs because the sense of safety is one of the most basic animal need. But once individual reaches certain level of self-awareness, they need to realise that every sense of safety in the material world is short-termed and delusional since everything ends with gradual decay and death. Since the solace from this fact cannot be pursued in the pragmatical sense (nothing can make us immortal) people resort to magical thinking or rituals to resort the sense of control and release the anxiety, to antropomorphising things that are beyond our power and control as 'God' (because if it's a person, we can engage in dialogue with it and we can please it and ask for its mercy) or to transferring their inborn archetype of "safe place" onto some conceptual other world or state of being (hence the concepts of "afterlife", "heaven", "nirvana") - since we still have the need for safety but are now smart enough to know it doesn't last for long in the material world. I think that most if not all religions' main purpose is to cater for those needs and that they are all pretty similar in the nutshell. Catholicism is more popular among my peers simply because it's there, it's familiar, it's been there for many generations. But I am not sure if it's the most optimal thing for the modern man to believe. I think that this religion is mainly anachronistic in its teachings. The Wisdom of New Testament was revolutionary in the times it has been created and that was certainly a milestone for humanity. Take the diversion from the preferential, selfish love into the non-preferential "love thy neighbour" type of love that has created the foundation for the concept of morality as something universal and utilitarian, rather than tribal. It must have been important and fresh for the people then, but now that we have absorbed this way of thinking about morality, digested it, raised few generations of children on it, I am not sure The Bible can teach us anything new by now. The same Jesus in the Gospel initially denies to heal the daughter of non-Jewish woman (saying that "dogs shouldn't eat from the table where children dine") or curses the fig tree to dry for it is fruitless in the time of the year when it is normal for it to be fruitless (I have always got the vibe from that parabola as if he didn't care if what he demands of his followers is above their abilities, his anger will fall at them if they fail anyway). Such fragments of The Bible annoyed me as I judged them from my modern mindset and that's why I think that XXI century's person has outgrown the figure of Jesus morally in the perception of "right" and "wrong" (whether the XXI century's person applies what they consider "right" and "wrong" to their everyday life is another thing, but well, that cannot be taught by any Holy Book I believe). Jesus is no moral authority anymore because he has nothing left to teach, what was universal and valuable in The Bible was absorbed by secular culture already and the rest is anachronistic - not fitting to the modern man's reality and problems.
Someone before has stated that The Bible is alive, only the symbolism in it is too cryptic for modern people to decipher. Like the "lamb of God" symbolism that one had evoked strong emotional response from people who sometimes really had to sacrifice the lamb in order to sustain their families or save the herd from the wolves. What I am really wondering is if the symbolism of this scene can be as that important for the modern European person at all, even after translating to a more modern language. It is not the language that is the problem for me here, it is the fact that life conditions have changed. Most people from The Western countries have troubles in conceptualising such harsh life when your physical safety from predators or hunger is your main concern. They don't know the value of community in leading such life. Today people are more preoccupied in more "subtle" problems like identity and value crisis in the multicultural world, feeling of existential emptiness, the problems with growing competitiveness among people, with civilizational diseases. Such things Catholicism doesn't address as during the time that Catholicism was formed, people had other things to worry about. I think it's the main reason that Christianity is now blooming in Africa, while it is quite stiff in Europe - it's just Europeans don't deal with the same issues as first Christians did anymore.
To sum up, I think people do need religion and always will need it but Catholicism is pretty much close to burning-out in Europe. I really hope it will get replaced or reformed as currently it promotes lots of prejudice, for example towards LGBT people. In my country we are one step from passing the bill that penalises the woman for trying to get an abortion (even due to medical reasons) - while I'm not pro-choice myself this is way overboard and it comes from religious fanaticism that doesn't even have anything in common with The Bible or with early Christianity.

For example, a classic example, if you were a train driver and your train spontaneously failed causing your breaks to stop working and people were on the two junction tracks. One person on the left and five people on the write. Which track do you take? Utilitarians will obviously say to take the left track with the one person on it sacrificing his life to save the five on the right track. This is because more people would be happy with the outcome as the quantity of people is greater in five than one. — GreyScorpio

This situation is not very good exemplification of controversies related to utilitarianism, because in this scenario, there is no way for the train driver to abstain from any killing, he has to choose the side. So it's not about killing one person or not, it's about killing one person or five people. Most people would agree instinctively that killing one person is lesser evil than killing five people in the situation when you literally cannot choose not to kill anyone, regardless of whether they are utilitarian or not. Perhaps the scenario in which the person can actively kill one person to save other five or abstain from action and let five people die would underline the issue better.

However, is it correct to be able to condone killing this way? — GreyScorpio

I think that question about correctness is always dependent on the set of criteria we choose. That is, we cannot know if any objective ethics exist independently of people developing ethics. We may only have some conceptions on what is "right" or "wrong", and judge the quality of those conceptions by their level of internal coherency. Hence, the question whether something is correct of not can be answered only within the frame of certain ethical conceptions. According to utilitarianism, yes, it would be correct. According to moral absolutist who lives under the "do not kill" rule it wouldn't be correct. Both attitudes can be internally coherent, and we can judge just that, what we cannot do is to tell which of those attitudes is closer to "objective moral truth".
Personally? I'm not sure if I condone killing the way that utilitarians do but as a biologist I think that condemning killing independently of context is hell of impractical and incoherent if we opt for the value of life at the same time. Life is based on killing and every life form has to kill in order to survive. Heterotrophic organism, such as humans need to kill other life forms in order to gain energy, but even autotrophic organisms kill others, for example during the immunological processes or through competing for the same resources and allelopathy. So the only coherent worldview that always ascribes negative moral value to killing would be the one that consequently ascribes negative moral value to life on itself. For people who consider life to be positive phenomenon on terms of morality, the question should not be "if it's correct to condone killing" but "under which circumstances should we condone killing?" since that's inevitable.

Not to mention other moral dilemmas of which utilitarianism would perhaps favor the side that is not socially moral. — GreyScorpio

Define "socially moral".