Wherever Christianity has become a living power, the doctrine of the Holy Spirit has uniformly been regarded, equally with the atonement and justification by faith, as the article of a standing or falling Church. The distinctive feature of Christianity, as it addresses itself to man’s experience, is the work of the Spirit, which not only elevates it far above all philosophical speculation, but also above every other form of religion.25 8. To know the Spirit is to be prepared for spiritual warfare.