There are many reasons not to be a Christian, or for that matter belonging to Islam or Judaism as well. First, let us make a quick review of some the logical arguments against the main tenet of Christianity, namely God. These logical arguments, or disproofs, seems impossible to escape unless one changes the rules of the game or, more commonly, changes the definitions of the words being used in the argument.
An all virtuous being cannot exist:
1. God is by definition a being which no greater being can be thought.
2. Greatness includes the greatness of virtue.
3. Therefore, God is a being that which no being could be more virtuous.
4. But virtue involves overcoming pains and danger.
5. Indeed, a being can only be properly virtuous if it can suffer pain or be destroyed.
6. A God that can suffer pain or is destructible is not one that which no greater being can be thought.
7. For you can think of a greater being, one that is nonsuffering and indestructible
8. Therefore, God does not exist
The problem of evil:
1. If God exists, then He is perfect
2. If God exists, then He is the creator of the universe.
3. If a being is perfect, then whatever he creates must also be perfect.
4. But the universe is not perfect.
5. Therefore, it is impossible for a perfect being to be the creator of the universe.
6. Hence, it is impossible for God to exist
A transcendent being cannot be omnipresent:
1. If God exists, then he is transcendent (i.e, outside space and time)
2. If God exists, he is omnipresent.
3. To be transcendent, a being cannot exist anywhere in space.
4. To be omnipresent, a being must exist everywhere in space-
5. Hence it is impossible for a transcendent being to be omnipresent.
6. Therefore, it is impossible for God to exist.
These are just a few examples of the many logical disproofs for the existence of God, but it gives some taste to the sheer formal absurdities of Gods existence. These arguments may not be considered very strong by some, but nevertheless they are there and perfectly valid, and they alone actually constitutes some nice arguments against one of the most central things in Christianity.
But lets not end our discourse with these simple formalities, but look at other aspects of Christianity as well. One of the attributes of God is that he has created the universe, thus the universe is designed. This is quite a common argument, and is a form of the "The God of the Gaps"-argument; the universe, and in particular living things, are simply too complex to have arisen by any conceivable natural mechanisms. This is, however, a huge fallacy. The theory of evolution renders this argument meaningless for many reasons. Biological data, as well as the whole realm of scientific observations lead to the conclusion that the universe is not at all designed. Indeed, Earth and life looks just as they can be expected to in the absence of a designer God - thus the hypothesis "God does not exist" is supported thouroughly by evidence.
For example, the discovery of human ancestors, DNA and anatomical connections between humans and other animals (even plants, too) falsify the hypothesis of a God who created humans as a distinct lifeform. The fossil record, the existence of transitional species, and the actual observation of evolutionary processes in the laboratory falsify the hypothesis of a God who created separate kinds or species of life at one time in history, while leaving them unchanged ever since. This is a strong and indisputable argument against the existence of the traditional Judeo-Christian-Islamic God. This God is simply absurd and falls under the weight of objective evidence and accumulated knowledge over the last few hundred years.
I could go on about how science actually shows how unlikely the traditional Judeo-Christian-Islamic God is, going into the depths of the arguments more thoroughly. But since a book would be needed to write it, lets just sum it all up:
1. A God who created the complex structure of the universe, especially that of life, fails to agree with the empirical fact that this structure can be understood to arise from simple natural mechanisms. As I've already said, everything we see is to be expected if no such creator God existed. Thus, it is highly unlikely that such a God exists.
2. A God who has given humans immortal souls fails to agree with the empirical fact that our memories and personalities are determined by physical processes in the brain (for example, damages to the brain can cause changes in personality), that no nonphysical or extraphysical powers of the mind can be found, and that no evidence for an afterlife exists. Thus, such a God is highly unlikely.
3. A God whose interaction with humans and the universe, including miraculous intervention, that is reported in scripture as well as elsewhere is simply contradicted by the lack of independent evidence that these events took place, and the fact that physical evidence now demonstrates convincingly that some of the most important biblical narratives, such as the Exodus, never took place.
4. A God who miraculously and supernaturally created the universe fails to agree with the fact that no violation of physical laws were needed to produce the universe, its laws, or its existence rather than its nonexistence.
5. A God who fine-tuned the laws and constants of physics for life, in particular human life, fails to agree with the fact that the universe is not congenial to human life, being tremendously wasteful of time, space and matter from our perspective. It also fails to agree with the fact that the universe is largely composed of particles in random motion, with complex structure such as galaxies forming less than 4 percent of the mass.
6. A God who communicates directly with humans through revelation fails to agree with the fact that no claimed revelation has ever been confirmed, while many have been falsified; no claimed revelation has contained information that could not have already been in the head of the person making the claim.
7. A God who is the source of morality and human values need not exist, because evidence clearly shows that humans define moral values themselves. Nonbelievers behave no less morally than believers.
8. The existence of evil is logically inconsistent with an omniscient, omnibenovelent, omnipotent God as shown earlier.
If a Judeo-Christian-Islamic God were to exist, at least some of these points shouldn't be contradicted by empirical observations and facts. But since all of these points fall under the weight of scientific observations, there is no reason to believe in such a fairy-tale God.
But there is more to argue against this God. For example he is, in fact, thoroughly evil because he deliberately encourages and commands his followers to kill, torture and abuse. Let us a look at a few passages from scripture:
Quote:If you hear that in one of the towns which Yahweh your God has given your for a home, there are men, scoundrels from your own stock, who have led their fellow-citizens astray, saying "Let us go serve other Gods," hitherto unknown to you, it is your duty to look into the matter, examine it, and inquire the most careful. If it is proved and confirmed that such a hateful thing has taken place among you, you must put the inhabitants of that town to the sword; you must lay it under the curse of destruction - the town and everything in it. You must pile up all its loot in the public square and burn the town and all of its loot, offering it all to Yahweh your God. It has to be a ruin for all time and never rebuilt
- Deutoronomy 13;12-16
Quote:If your brother, the son of your father or of your mother, or your son or daughter, or the spouse whom you embrace, or your most intimate friend, tries to secretely seduce you, saying "Let us go serve other gods," unknown to you or your ancestors before you, gods of the peoples surrounding you, whether near you or from far away, anywhere throughout the world, you must not consent, you must not spare him or conceal his guilt. No, you must kill him, your hand must strike the first blow in putting him to death and the hands of the rest of the people following. You must stone him to death, since he has tried to divert you from Yahweh your God
- Deutoronomy 13;7-11
More nice passages can be found everywhere in the Bible, and for your amusement you may also take a look at
New Testament Cruelty. For a taste, Jesus has this to say about Jews;
Quote:But the children of the kingdom shall be cast out into outer darkness: there shall be weeping and gnashing of teeth.
- Matthew 8;12
Jesus is not such a nice guy after all, is he now? Not at all:
Quote:Think not that I am come to send peace on earth: I came not to send peace, but a sword. For I am come to set a man at variance against his father, and the daughter against her mother, and the daughter in law against her mother in law.And a man's foes shall be they of his own household. He that loveth father or mother more than me is not worthy of me: and he that loveth son or daughter more than me is not worthy of me.
- Matthew 10;34-36
Is it really a nice thing to worship such a God and such a man? When they want you to kill, to spread suffering, to torture and abuse, why would you want to believe in them? It's insane. Passages like this can be and have been used to kill and torture in the name of God and Jesus - for example the Inquisition, the hunting of witches and the Anti-Semitism inherent in Christianity. Christianity is repulsive and barbarian, totally stripped from reason and critical thinking, and is simply primitive. It is also currently a great obstacle to scientific research in the United States (stem cell research in particular), and an opponent of gay-marriage among other things. Furthermore, under the influence of Christian notions of the sinfulness of sex outside of marriage, the U.S. government has earlier required that one-third of its AIDS prevention funds allocated in Africa be squandered on teaching abstinence rather than condom use. Millions could die as a direct result of this stupid religiuos dogmatism. The list goes on of these repulsive actions where reason is abandoned.