I know it sounds odd, but it seems to me that it is perfectly possible for a Christian to be an active atheist. Of course, not in the way that we normally use the term – meaning: someone who intellectually or emotionally does not believe in the existence of God. No, I mean in the way that the Bible perceives of the atheist: a person who lives as though there was no God. “The fool” who says in his heart, “There is no God!” (Psalm 14:1) is not an intellectual atheist, but a practical one. The term ‘fool’ as used in the wisdom literature of the Bible is not an ‘idiot’ but a person who has chosen an immoral path. He behaves as though no-one is watching him, as though there were no consequences to sinful actions, and no day of judgement. In that regard, the most devout Christian can have a season, or even a daily lifestyle, of atheism mixed in together with their Sunday faith. We need to guard against it.
Psalm 14 goes on to tell us what this “foolish” practical atheism does to a person’s heart. He or she performs vile deeds (verse 1), has a prayer-less life and neglects to seek God (verses 2-3), despises people (verse 4), lives in fear (verse 5) and exploits, or at the very least has no concern, for the poor (verse 6). By these standards, I’d say we all ought to watch out for atheism.
I was once challenged with this thought: Don’t tell me what you believe. Tell me what you do. Then, I will be able to tell you what you believe. So, do you believe in God?