Concept of God
The concept of God, or the 'God concept', is the logical, or mental, picture of an 'ideal being', or the 'greatest possible being'. It is a natural concept, in that it is the opposite of what we creatures know of all other beings, including of ourselves: we are not the ideal, or the greatest possible, being.
Features of the God concept
Perhaps the first feature of the 'God concept' is ontological originality. This feature is that which is the opposite of ontological contingency. Everything we observe of the world around us is contingent upon, that is, caused by, something else; and, we have a natural sense that there must be something which is, in itself, not caused by anything, but which exists necessarily and always.
A second feature of the 'God concept' is ontological immutability, or the unchanging-ness of the ideal being. If the ontologically original being changed in its own being, in its own nature, then it would not be the ideal being, and, moreover, its change-ability would mean that there is nothing that can be strictly true or good, and, thus, nothing that can be strictly false or bad. In contrast to the 'God concept', and especially to ontological immutability, there is postmodernism and paganism, which are philosophical worldviews in which there is always a struggle to determine what is strictly true and good by the sole means of compromise, a means which otherwise is known as pragmatism. Ontological immutability is the essence of universal truth, and, hence, of truths about the nature of a given kind of contingent being. Unless all possible beings are change-able in their natures, no creature is purely change-able in its nature. Even evolutionism admits that there must be a limit to the maximum rate of change of a given kind of creature, and to other features of that creature's change-ability, otherwise evolutionism could never seem to anyone to be tenable.
A third feature of the 'God concept' is mind, or 'knowing'. If there is no immutable original being, then all minds can be changed, and in any way, and even all rules of reasoning can be changed.
A fourth feature of the 'God concept' is love, or benevolence. In the tradition of scientism, love is subjective and therefore of no scientific value. But, since love exists as such, then love neither is unscientific nor is subjective. The only subjectivity in regard to love is in what a given creature can mistakenly think that love requires of a given being in a real set of circumstances (irrespective of what that given creature may think is the complete set of circumstances).
A fifth (and sixth) feature of the 'God concept' is omnipresence (and transcendence). God's omnipresence is typically held by Conservative Christians to be, at least, a complimentary contrast to God's transcendence, though most other religions find these two features to be more-or-less in strict (non-complimentary), or mutually exclusive, contrast.