Why are you (still) a Christian?

[Data]

Atheism is the absence of any theism. 
Whatever you can imagine as theism, is not present in atheism.

The consideration of gods.  

It's why many of us are igtheists.
There is no coherent definition of a god

In my own words a god is anything or anyone venerated. In Oxford's dictionary a god is

1. (in Christianity and other monotheistic religions) the creator and ruler of the universe and source of all moral authority; the supreme being.

2. (in certain other religions) a superhuman being or spirit worshiped as having power over nature or human fortunes; a deity.

an image, idol, animal, or other object worshiped as divine or symbolizing a god.
"wooden gods from the Congo"

used as a conventional personification of fate.
"he dialed the number and, the gods relenting, got through at once"

3. an adored, admired, or influential person.
"he has little time for the fashion victims for whom he is a god"

a thing accorded the supreme importance appropriate to a god.
"don't make money your god"

4. INFORMAL
the gallery in a theater.