Belief in a higher self is essential for normal human beings. I believe that few true atheists (loosely defined) exist. Most people who think they are atheists merely have a problem with the definition of God. The label ‘God’ is loaded with all sorts of dogmatic implications. The term ‘Higher Power’ is used by 12-steps groups but is not without its own problems. I sometimes prefer thinking of God as a ‘Higher Self’. Anyone who believes that there are things in this universe more important than themselves believes in a higher self. Anyone whose sense of self extends beyond their immediate individuality – such as family, community, humanity, life, totality – believes in a Higher Self. Perhaps only sociopaths can be atheists in this sense. [1 Corinthians 3:16]
Introverted seekers need introverted evangelists. It's not that extroverts can't communicate the gospel, either verbally or nonverbally, in ways that introverts find appealing, it's that introverted seekers need to know and see that it's possible to lead the Christian life as themselves. It's imperative for them to understand that becoming a Christian is not tantamount with becoming an extrovert.