Spiritual development is the dissolution of past conditioning and the weakening of the ego. Spiritual progress occurs when you free your awareness from the limitations of thought and connect with the divine directly.
Your past conditioning forms the ego. And it is the ego that gives you the false impression that you exist only within the confines of your physical body and apart from everything in the external world.
In order to make spiritual progress you must free yourself from the ego’s control. The ego is sustained by thoughts in the mind. As long as you are thinking you are controlled by the ego and unable to experience the deeper reality.
A spiritual practice enables you to still the mind so you can perceive the deeper reality. By focusing on the deeper reality, and through divine grace, your past conditioning is dissolved and the ego is weakened. When all of your past conditioning is gone the ego is destroyed and you attain liberation. Then you are always aware of your oneness with the deeper reality that sustains all forms in creation.
Most people in the west don’t progress spiritually because they are unable to free their awareness from the limitations of the ego and the thinking mind. They never learn how. It is not taught in school or in church.
Some of major world religions don’t emphasize spiritual development. And they don’t even address the ego, which is the major impediment to spiritual progress. Instead they talk about the importance of faith and beliefs. They focus on ideas that exist only within the confines of the mind. And as a result they remain under the ego’s control and unable to connect with the deeper reality.
It is important to recognize that spiritual development only occurs from the perspective of the ego. From the perspective of the soul, you are always one with the infinite. The spiritual path is the process of consciously perceiving this oneness.