Is a belief in rebirth a necessity for Buddhist practice?

Yes. View of rebirth is a part of Right View, but only at the later stages, after one sees for oneself that rebirth is real. Read The Noble Eightfold Path by Bhikkhu Bodhi.

According to the Buddhism, "Next Birth" is not the person who lives in this birth. In the next birth, there is a person determined by the previous Karma.

For certain concepts to be describe in particular in anicca it is needed to believe reincarnation.

All of what we are ends with this birth. Only goodness and evil are taken to the next birth. So there is need to believe it for this reason.

For instance, If we are having good wealth and satisfaction through all the ways, we may think life is so happy and funny. But it is due to the meritorial deeds you have done in your past births. The effects of those good merits will end in one day. At the end of this birth or in future births. No one will be a good person all over his Sansara. So one day comes where you have to encounter sadness.

From here:

§ When I first went to practice meditation with Ajaan Fuang, I asked him if people really were reborn after death. He answered, "When you start out practicing, the Buddha asks you to believe in only one thing: karma. As for things aside from that, whether or not you believe them isn't really important."

You may find the Apannaka Sutta MN 60 (A Safe Bet) helpful to answer your question. Here the Buddha talks about the benefits of not rejecting the possibility of rebirth.

"As you have not found an agreeable teacher, you should adopt and practice this safe-bet teaching, for this safe-bet teaching — when accepted and adopted — will be to your long-term welfare & happiness.

"And what is the safe-bet teaching?

http://www.accesstoinsight.org/tipitaka/mn/mn.060.than.html

Chong An Sunim talked about this in one dharma talk by saying how people ask him if rebirth exist or not. He said he replies, "what is it that you want? If you want rebirth, you have it. If you don't want it, you don't have it."

Rebirth is just a teaching word. It is there only to give you some intellectual understand of what is going on. In Zen, finger is pointing to moon. There is no need to argue whether finger is worth belief or not. Use it as tool and look at the moon.

Don't use rebirth as belief. Don't use it as non-belief. Use it as stepping stone. Use it as aid. Buddhism is about practice. You can only truly understand meaning and ultimate reality behind this concept by seeing it clearly as it is. And that is not depended upon whether you believe in it or not. Both of those views can be hindrance in seeing how reality really is.

Thus belief in rebirth or reject of rebirth are both wrong views. Any kind of idea you have about rebirth is just idea and in Buddhism all ideas are wrong ideas. Don't believe. Don't reject. Just use it as instruction manual. Aim to see clearly and past all of these concepts because ultimate reality does not support existence of these concepts.

Instead of existence of rebirth it could be more beneficial to meditate and contemplate the definition of rebirth. What is being reborn? When? How?

So in short is a belief in rebirth a necessity for Buddhist practice?

After going through all the responses above I was very much satisfied with what Jayantha has said. I would like to add something to this discussion - I think rebirth is part of Buddhist doctrine. But the real question is rebirth of what? and rebirth of whom?

According to the Buddha, there are four elements of Existence which go to compose the body. They are (1) Prithvi; (2) Apa; (3) Tej; and (4) Vayu. Question is, when the human body dies, what happens to these four elements? Do they also die along with dead body? According to The Buddha they join the mass of similar elements floating in (Akash) space. When the four elements from this floating mass join together, a new birth takes place. This is what the Buddha meant by rebirth, as I have understood it. It must be noted that the body dies. But the elements are ever-living. This is the kind of rebirth in which the Buddha believed. Great light is thrown upon the subject by Sariputta in his dialogue with Maha-Kotthita. The Buddha was not an absolute annihilationist. He was an annihilationist so far as soul was concerned. He was not an annihilationist so far as matter was concerned. (I think Andrei Volkov is also saying the same point when he is talking about "complete annihilation).

There is another concern here. It is about rebirth of Whom? Does the same dead person take a new birth? Did the Buddha believe in this thesis? The answer is, "Most improbable." The answer depends upon the elements of existence of the dead man meeting together and forming a new body; then the possibility of the rebirth of the same sentient being is possible. If a new body is formed after a mixture or the different elements of the different men who are dead, then there is rebirth but not the rebirth of the same sentient being. This point has been well explained by sister Khema to King Pasenadi. Where she ends up saying 'The Tathagata exists after death...exists not after death', does not apply." (Again we can match Jayantha's write up regarding Kalama Sutta.) I have drawn lot from Buddha and His Dhamma Book 4, Part 2, section 1, sub section 2. Hoping for further discussion.

Most of the answers say "No" but I would like to offer a different point of view eventhough it will not be popular, sorry!

The key concept of Buddhism are the 4 Noble truths. They are shared by all schools and were part of the first discourse of the Buddha, the 4 Noble truths are so important that they keep appearing over and over again in many suttas.

I cannot see how can one be a Buddhist disagreeing our doubting the 4 Noble truths. So, if you check them you will see that is not possible to agree with them and at the same time disagree with the idea ofthings like samsara, rebirth, etc

The first thing Buddha said after enlightment (is in the dhammapada) was: " I have gone round in vain the cycles of many lives ever striving to find the builder of the house of life and death. How great is the sorrow of life that must die!"

The 1st Noble truth is not about ordinary suffering only, but mostly about ageing, sickness and death (and rebirth! and lower realms!)

Scaping from Samsara by achieving Nibbana is also part of the noble truths... so if you think about it carefully you may see that: Yes, it is necessary to believe in those things to accept the Noble truths and without the Noble truths I cannot see how can one be a Buddhist (can be a nice person for sure, but not a followr of the Buddha)

Buddha said this verse in Dhammapada 176 to show the importance of it: "For a liar who has violated the one law (of truthfulness) who holds in scorn the hereafter, there is no evil that he cannot do."

Rejecting rebirth is part of wrong view. Rejecting rebirth hence is also an unwholesome deed. But, being 'agnostic' you don't need to reject rebirth, you may just put this belief on hold. I don't see, though, how can you understand and appreciate karma at full without belief in rebirth. If there is no rebirth it may reasonably follow that you can avoid results of unwholesome deeds if you are astute enough.

From other point of view, I think, from Abhidharmic perspective, if we strictly follow dharmical analytical view, then belief in rebirth is not that important, because in that perspective 'being' and 'death' are not real existents and just conventional truth, there will be just indefinite long stream of consciousness (santana) where karma fruits will necessarily appear for every action (cetana). From the same perspective we can presume that we are already rebirthing every moment.

This is more a question of the meaning of words than of doctrine or practice per se. If one defines "Buddhism" to include a belief in re-birth, then you can't have the former without the latter. But if not, then otherwise. The problem is, there is no precise, universally accepted definition of "Buddhism". As Jayantha points out, so-called "secular" Buddhism doesn't tend to have a belief in re-birth. Now some people would reply that in that case "secular" Buddhist's aren't actually Buddhists -- the No True Scotsman position (because, as I said, there is not a universally accepted definition), but that's just begging the question.

An analogy could be to ask if someone could be a Christian without believing in the divinity of Christ. The majority of people calling themselves Christian would say you cannot, but Christadelphians would say you can. Again, many Christians would then say, as a result, that Christadelphians are not "real" Christians. Again; question begging.

So, is it possible to meditate without believing in re-birth? Yes. Without believing in re-birth...

• ...is it possible to practice and develop compassion? Yes.
• ...is it possible to hold the Buddha's teaching in high esteem, but to see "re-birth" as simply a metaphor? Yes.
• ...is it possible to achieve a high level of "attainment" -- advanced samadhi, highly developed insight and so on? Yes, apparently so.

However, is a person missing something significant if re-birth is true but they don't see that and act accordingly? I'd say, absolutely.

As I result, personally I concur with @Jayantha's approach -- currently I don't know but I have an open mind. I'm also taking care to understand what the Buddhist view of "re-birth" actually is. It's widely misrepresented (as is, to go back to my analogy, the exact nature of Christ's alleged "divinity"). The more I look at Buddhism, the more I realize that the popularized ideas often vastly oversimplify what are actually very deep and subtle concepts, with far more scope for being true and consistent with my mainline western-science-based upbringing than I had at first thought when viewing them from a distance.

No, believe in literal rebirth is not necessary, as long as you don't subscribe to the other extreme -- that of complete annihilation at the time of death.

That said, Buddha greatly appreciated the concept of rebirth as a practical motivator. He compared fear of unfortunate rebirth with fear of punishment that stops a potential criminal from committing a crime.

One of my teachers (an ordained Korean Zen master) did not assert literal rebirth, stating instead that rebirth happens every moment. My other teacher explicitly said that rebirth/karma is a metaphor for information carried on from one life to another through natural means.