"Spiritual desires for God render the service spiritual; when the soul 'follows hard after him' (Psalm lxiii. 8); pursues after God as a God of infinite and communicative goodness, with sighs and groans unutterable. A spiritual soul seems to be transformed into hunger and thirst, and becomes nothing but desire. A carnal worshiper is taken with the beauty and magnificence of the temple; a spiritual worshiper desires to see the glory of God in the sanctuary (Psalm lxiii. 2), he pants after God; as he comes to worship, to find God, he boils up in desires for God and is loath to go from it without God, 'the living God' (Psalm xlii. 2). . . . That deserves not the title of spiritual worship, when the soul makes no longing inquiries, 'Saw you him whom my soul loves?' A spiritual worship is when our desires are chiefly for God in the worship; as David desires to dwell in the house of the Lord; but his desire is not terminated there, but to behold the beauty of the Lord (Psalm xxvii. 4), and taste the ravishing sweetness of his presence. . . . To desire worship as an end is carnal; to desire it as a means . . . is spiritual and the fruit of a spiritual life."
Stephen Charnock, Discourses upon the Existence and Attributes of God, I:232-233.