For religious believers, the concept of God is attended by a sense of percieved profundity. That is to say, religious discourse, or discourse using the word God is qualitatively different from ordinary discourse. When confronted with such a concept, we can not only define more or less exactly what is meant, but we can also point to several instances both of what does and does NOT count as a specific example to which the concept refers. The concept of God is very different. It is a concept whose referent is not fixed or easily definable.
Different believers attach entirely different meanings to the concept.
Some concieve of God in highly anthropomorphic man-like terms, complete with a voice, a face, and a hand, etc. For some, God is concieved as an entity who can have a definite position in space, such as Mount Olympus, while for others God is said to be outside of space-time altogether. Without first knowing, more or less precisely, what we mean by the word 'God,' no meaningful discussion can follow. In order to understand what, if anything, is denoted by the concept of God, it is necessary to analyse the concept itself. For any concept to be intelligible at all, it most not entail a contradiction.