That moral change, that spiritual renovation, which has been called CONVERSION, is, we are aware, and ever will be, the subject of profane ridicule amongst unbelievers. It does not indeed produce any astonishment, although it awakens extreme regret, that one of the most obvious effects resulting from the publication of the Gospel of Christ should be so unblushingly denied by this class of mankind. "The natural man discerneth not the things of the Spirit of God, because they are spiritually discerned." The scriptures themselves predict this incapacity, even in some of the most refined and intellectual of our species, to form a conception of this marvellous change; and experience evinces the truth of what they affirm, and which originates in the very nature of things. It is characteristic of human perversity to disbelieve what is imperceptible to reason or invisible to sense, and to vaunt itself upon that very infidelity as a distinctive mark of pre-eminence, which is, in fact, a proof of debasement and guilt. If a system of religion were to be so constructed as to be exempt from the ridicule of the profane, it must be itself ridiculous; because their distorted minds cannot discern the beauties of truth, and their depraved feelings will not admit her claims. To secure their approbation religion must change her character, alter her doctrines, new cast her precepts, and new modify her principles. Lydia presents an interesting specimen not only of the reality but of the nature of the great work of conversion; and, however contemptible the subject may appear in the eye of a dissipated world, or to the mind of a prejudiced reader, we hesitate not to state the sentiments which necessarily arise out of the present example respecting the seat and source of this change, the agent by whom it is accomplished, and the corresponding effects produced. 1. Our attention is, in the first place, to be directed to _the seat of this spiritual renovation_. It is said of Lydia, that her HEART was opened. This change, therefore, is of a moral nature, not merely circumstantial, but radical. It does not consist in assuming a new name, professing new opinions, using a new language, performing a few rites and ceremonies, or reforming a few exterior vices, These are only branches--the tree itself must be made good--the crab stock of nature must be grafted with spiritual principles, and by being planted in the garden of the Lord be brought under a heavenly culture. It is then only "the fruits of righteousness" may be anticipated, "which are to the glory and praise of God."