Glossary
Spiritual
The word spiritual does not refer to the vaguely mystical and otherworldly, or to some religious and indefinable aspect of human nature, as it is somtimes taken to mean in popular usage. It may refer to that which is immaterial but nonetheless real; God is spirit, and there are spirit beings (angels and demons). Indeed there is a whole, immaterial, invisible realm which is 'spiritual' - sometimes referred to as the heavenly realms and crucial to understand and apprehend for the life of faith.
However, the most important meaning of the word spiritual is 'of the Spirit.' It is that which is born of, inspired by, under the influence of or expressive of the Spirit of God. So to be spiritual is to be someone who is living by the Spirit. Something that is said to be spiritual may be immaterial but it will also often mean 'of the Spirit' in contrast to 'of this world.' This is because the Spirit is the one who makes real to us the things of the Kingdom, something of the age to come, in oppostion to that which is of this world and of this age. The things of the Spirit are eternal while the things of this world and age are passing away.