Spiritual development is moral development. It's the movement from division to wholeness. Most of us are deeply divided, which means we have mixed motives. This is why most of us are untrustworthy. Under pressure, the self divides and suddenly you don't know who a person is; you don't know what they are going to do. So when we become interested in evolving, we have to begin to face this deep division within ourselves. We have to confront the darkest motives that exist within us, the deeply unwholesome drives of the ego, and we have to emotionally get in touch with the effect we have on those around us when we act from those motives.
As we evolve, we become a lot more sensitive to the deeply destructive nature of ego, in ourselves and in others. That's the awakening of conscience—a higher conscience that has nothing to do with ego but comes from the level of the soul. But it takes humility to develop at this level. Most of us cherish a self-image that has very little to do with how we really are. When the true picture is revealed, some people come to their knees in humility. Others fall into a narcissistic rage, unable to bear the truth. It's at moments like these, when there is tremendous evolutionary pressure, that the self divides.
If you make a decision to remain whole under pressure, to face the truth without wavering, what emerges is literally a new human being. You discover self-confidence, spiritual and moral strength, self-respect and dignity. That's soul development. But it takes a tremendous commitment and a deep surrender to resist the temptation to divide. If the self doesn't divide under pressure, then evolution takes place in real time.