It is impossible to evaluate the position of atheism in modern times without analyzing the nature of human knowledge and our knowledge of God. Therefore we must first keep in mind that there are basically two sources of knowledge of God.
(a) The philosophical arguments for the existence of some transcendent Source of all reality like the idea of the Highest Good in Plato, the idea of the First Mover and the First Cause in Aristotle and also the development of Thomistic philosophy which to a great extend is an adaptation of Aristotelian thought to the basic dogmas of Christian religion. This would be the philosophical underpinning of religious faith. The great systems of Plato, Aristotle or Thomas Aquinas are based on the acceptance of intelligibility of all being as such and they are metaphysical in nature.
(b) The second and more fundamental source of religious belief is based on revelation. Revelation is the unveiling of God himself to human beings and therefore humans are given some insight into the nature of God, His will and purposes and also their relationship to God's purposes and intentions. For example to be a Christian does not necessarily demand philosophical knowledge of God. One believes because in the person of Jesus Christ God became a human being , human in all things human except sin. Christ therefore is the revelation of God in the most possible way identified with the suffering servant of the Father. Christ's Crucifixion and Resurrection is God's salvific lifting every believer to the state of adapted child of God with the promise of eternal life after physical death and future resurrection for eternity. As pointed out above, the Christian believer does not have to be a philosopher, but St. Paul insists very clearly that a Christian must be able to give some reasons why he/she believes, that is must be able to defend his commitment to the message and promises of Christ.
Let's analyse first the philosophical knowledge of God and it's possibility . This problem is extremely important especially after the modern atheists which deny any possibility even of proving the rationality of believing in God. The widely spread belief of modern scientists and also some philosophers is that only scientific methods are fruitful ways of any knowledge whatsoever. This position leads directly to scientific reductionism , rejection of any metaphysical thinking , to skepticism and quite often crude materialism. This attitude is not only part of modern physics but also psychology, psychiatry and biology with the propagated theory of evolution of all life in the Darwinian way of understanding. Ultimately this dogmatic scientific attitude leads to the conviction that science alone will soon explain all phenomena of nature without any need for some transcendent or Divine reality.
According to this way of thinking science supposedly deals only with bear facts (phenomena) and it does not show any interest in values of man, meaning of human existence or destiny of individual persons. Briefly the whole area most personal and essential for every reflecting human being is a neglected field of interest.
Human beings are not only interested in for example how many new galaxies were recently discovered by some astronomer or whether our solar system is doomed to thermal death in perhaps several billion of years. Those are scientific facts but they do not touch the deepest questions , like who am I ? , why do I exist? what happens when I die? Is there any sense i praying to some God if we don't know if He even exists? It certainly would be nonsense to pray or make any sacrifices if there is nothing but matter in space-time. Nor is there any solid reason for moral values of any kind apart from sophisticated selfishness during this short journey from the womb of a woman to the womb of mother earth. As Dostoevsky once remarked : If God does not exist everything is allowed!. What did he have in mind when saying this is easy to understand : without some transcending Divine authority the human values are reduced only to the level of the human way of behavior and consequently very often the moral values will be simply turned into some ideological tool of human domination of one group of people who happen to be in power over those who are considered undesirable elements in the society. A classic example of this fact is the history repeated again and again of mass extinction organized by such movements like for example Hitlerism , Stalinism and so many others. We don't have to agree with Dostoevsky in many other things he said but here he certainly was right. The philosophy of Thomas Hobbes : "Homo homini lupus " should not be forgotten or else we lose a realistic vision of man and his dark sides and destructive instincts .
We mentioned already that in our analysis of human knowledge we must remember always the dynamism of the human mind and the basic presuppositions of any true inside into reality. In practice this means that a modern scientist, a physicist, an anthropologist or a paleontologist does not have to be a schizophrenic when he does his scientific work but also is a believer in God and participates in some religious rituals . Why so ?. Because he has the same human mind like anybody else which he uses rationally and fully in both situations: as a scientist and a believer. This is important to remember when one is confronted with all those who say that science replaces the concept of God and makes God obsolete because the scientific method shall explain all questions of man in a rational way without any need for belief in any kind of transcendent reality, spiritual in nature . For such people all is nothing else but matter in movement and change and any questions for something else like for example the mental aspects of reality are superfluous and outdated. Those trends in modern thinking must be corrected and there is only one way of doing this by a very thorough analysis what is knowing in itself.
Any analysis whatsoever starts with some basic assumptions from a definite vantage point . Here we assume that man exists, that he has an active mind and he is able to know reality following basic given principles of knowledge. Those principles are self evident statements, which do not admit serious doubt : the principle that nothingness can never produce anything real, that whatever exists must have sufficient reason for it's existence, that nothing can exist and not exist at the same time under the same respect, that in order to know somehow reality the mind must follow logical method of discovery. This therefore will be our starting point of analysis. We do it to avoid idealism , materialism , skepticism and scientific reductionism. The level on which we shall move is the knowledge of being and it's intelligibility . When later on we shall discuss some religious modes of understanding the human situation, we must be careful to avoid such views like: panenteism,pantheism and anthropomorphic understanding and distortions of the idea of God. But now let's apply our basic presumption in knowledge and discuss them on the existential level. The approach we shall adopt can be described as methodical realism . The central concept here is the concept of being and the ability of the human mind to understand being in it's all forms available to human insight.
In passing let's just notice that the ancient and medieval thinkers like Socrates, Plato , Aristotle or Thomas Aquinas never doubted the capacity of understanding the ultimate reality by the human mind. The doubt developed in modern times with Rene Descartes, who applied his methodical doubt to all knowledge including his own existence and then somehow rediscovered it : " I think therefore I am." This sentence has been repeated later on by many philosophers especially the Cartesians. However was it really such a big discovery? One immediately can see that Descartes would not be able to say anything or doubt anything unless he first already existed. It brings into the mind a little story: In philosophy class when a student asks the professor : " How do I know I exist? The professor simply says : "Who is asking?." That means if you did not exist you would not be able to ask such a question. Read Part III