When asked to prove God's existence, the Christian will often open the Bible and say "The Bible says God exists, so he must." The problem is that if we ask a Hindu, a Muslim, a Sikh or a Jew the same question they too will point to their respective holy books as proof of the existence of their Gods. Why should we believe the Bible but not the holy books of all the other religions? Using the Bible to prove God's existence is only valid if we already accept that it alone contains God's words. However, we have no evidence that this is so. In fact, as we will demonstrate later, there is strong evidence that the Bible is a highly unreliable document.
In their attempts to prove God's existence, Christians will sometimes say "The universe didn't just happen, someone must have made it and therefore there must be a creator God." There is a major flaw in this argument. When it starts to rain ~e do not ask "Who is making it rain?" because we know that rain is caused not by someone but by something - natural phenomena like heat, evaporation, precipitation, etc. When we see smooth stones in a river, we do not ask "Who polished those stones?" because we know that the smooth surface of the stones was caused not by someone but by something - natural causes like the abrasive action of water and sand.
All of these things have a cause (or causes) but this need not be a being. It is the same with the universe - it was not brought into being by a God but by natural phenomena like nuclear fission, gravity, inertia, etc. However, even if we believe that a divine being is needed to explain how the universe came into existence, what proof is there that it was the Christian God? Perhaps it was created by the Hindu God, the God of Islam or one of the gods worshipped by tribal religions. After all most religions, not only Christianity, claim that their God or gods created the universe.
In response to the above refutation, the Christian will maintain that the universe does not merely exist but its existence shows perfect design. There is, a Christian might say, an order and balance which point to its having been designed by a higher intelligence, and that this higher intelligence is God. But as before, there are some problems with this argument.
Firstly, how does the Christian know that it was his God who is behind creation? Perhaps it was the gods of non-Christian religions who designed and created the universe.
Secondly, how does the Christian know that only one God designed everything? In fact, as the universe is so intricate and complex we could expect it to need the intelligence of several, perhaps dozens, of gods to design it. So if anything the argument from design proves that there are many gods, not one as Christians claim.
Next, we would have to ask, is the universe perfectly designed? We must ask this because if a perfect God designed and created the universe, then that universe should be perfect. Let us first look at inanimate phenomena to see whether they show perfect design. Rain gives us pure water to drink but sometimes it rains too much and people lose their lives, their homes and their means of livelihood in floods. At other times it doesn't rain at all and millions die in drought and famine. Is this perfect design? The mountains give us joy as we see them reaching up into the sky. But landslides ~nd volcanic eruptions have for centuries caused havoc and death. Is this perfect design? The gentle breezes cool us but storms and tornadoes repeatedly cause death and destruction. Is this perfect design? These and other natural calamities prove that inanimate phenomena do not exhibit perfect design and therefore that they were not created by a perfect God.
Now let us look at animate phenomena to see whether they reveal perfect design. At a superficial glance, nature seems to be beautiful and harmonious; all creatures are provided for and each has its task to perform. However, as any biologist will confirm, nature is utterly ruthless. To live, each creature has to feed on other creatures and struggle to avoid being eaten by other creatures. In nature, there is no time for pity, love or mercy. If a loving God designed everything, why did such a cruel design result? The animal kingdom is not only imperfect in the ethical sense, it is also imperfect in that it often goes wrong. Every year ~lions of babies are born with physical or mental disabilities, or are stillborn or die soon after birth. Why would a perfect creator God design such terrible things?
So if there is design in the universe, much of it is faulty and cruel. This would seem to indicate that the universe was not created by a perfect all-loving God.
Christians will sometimes say that everything has a cause, that there must be a first cause, and that God is the first cause. This old argument contains its own refutation, for if everything has a first cause then the first cause must also have a cause.
There is another problem with the first cause argument. Logically there is no good reason to assume that everything had a single first cause. Perhaps six, ten or three hundred causes occurring simultaneously caused everything.
Christians claim that miracles are sometimes performed in God's name and that the fact that this happens proves that God exists. This is an appealing argument until it is looked at a little more closely.
While Christians are quick to claim that because of their prayers the blind could see, the deaf could hear and crooked limbs were straightened, they are very slow in producing evidence to back up their claims. In fact, some Christians are so anxious to prove that miracles have occurred at their prayer meetings that the truth often gets lost in a flood of wild claims, extravagant boasts, and sometimes even conscious lies.
It is true that things which are unusual and difficult to explain do sometimes happen during religious events - but not just for Christians. Hindus, Muslims, Taoists, etc. all claim that their God or gods sometimes perform miracles. Christianity certainly does not have a monopoly on miracles. So, if miracles performed in God's name prove the existence of the Christian God, then miracles performed in the name of numerous other gods must likewise prove that they too exist.
Christians may try to overcome this fact by claiming that, when miracles occur in other religions, they are done through the power of the Devil. Perhaps the best way to counter this claim is to quote the Bible. When Jesus healed the sick, his enemies accused him of doing this through the power of the Devil. He answered that healing the sick results in good and if the Devil went around doing good he would destroy himself (Mk 3:22-26). Therefore the same could be said for the miracles performed by Hindus, Jews or Sikhs. If these miracles result in good, how can they be the work of the Devil?
Christians will often claim that only by believing in God will people have the strength to deal with life's problems, and therefore that belief in God is necessary. This claim is apparently supported by numerous books written by Christians who have endured and overcome various crises through the power of God. Some of these books make highly inspiring reading, so the claim that one can cope with problems only with God's help sounds rather convincing - until we look a little more deeply.
If this claim is true, we would expect most of the non-Christian people of the world to lead lives of emotional distress, confusion and hopelessness while most Christians through their faith in God would be able to unfailingly deal with their problems and to never need to seek help from counsellors or psychiatrists. It is clear, however, that people from non-Christian religions and even those with no religion are just as capable of dealing with life's crises as Christians are sometimes even better. It is also sometimes the case that people who are devout Christians lose their faith in God after being confronted with serious personal problems. Consequently, the claim that belief in God is necessary to cope with and overcome problems is baseless.
When Christians find they cannot prove God's existence with doubtful facts or logic, they may switch tactics and say "Perhaps it can't be proved that God exists, but neither can you disprove it". This of course is quite true. You cannot prove that God doesn't exist - but neither can you prove that the gods of Taoism, Hinduism and a dozen other religions do not exist. In other words, despite all the hyperbole, the extravagant claims and the confident proclamations, there is no more evidence for the existence of the Christian God than there is for the gods worshipped in other religions.
After everything else has failed, the Christian may finally try to convince us that God exists by appealing to the emotions. Such a person will say, perhaps quite truthfully, "I used to be unhappy and discontented but after giving myself to God I am happy and at peace with myself." Such testimonies can be deeply moving, but what do they prove? There are millions of people whose lives became equally happy and meaningful after they embraced Buddhism, Hinduism or Islam. Likewise, there are no doubt many people whose lives have not changed for the better after they became Christians - the same weaknesses and problems sometimes remain. So this argument, like all the others, does not prove the existence of the Christian God.