Charles H. Spurgeon on Psalms 15:1

The disguising and counterfeiting of hypocrites in all ages, occasioned haply this query: for, as Paul speaks, "all are not Israel that are of Israel," a great many living in the church are not of the church, according to that of the doctors upon this place, multi sunt corpore qui non sunt fide, multi nomine qui non sunt nomine. Wherefore, David, here perceiving that sundry people were shuffled into God's tabernacle like goats among the sheep, and tares among the corn, being Jews outwardly, but not inwardly, deceiving others often, and, sometimes, themselves also, with a bare profession of religion, and false opinion of true piety, cometh unto God (as to the searcher and trier of the hearts of men, acquainted with all secrets, and best understanding who are his own), saying unto him, O Lord, forsomuch as there is so much unsoundness and hypocrisy reigning among those that dwell in thy tabernacle, professing thy word, and frequenting the places of thy worship; I beseech thee most humbly, to declare to thy people some tokens and cognizances by which a true subject of thy kingdom may be discerned from the children of this world. Here then, observe, that an external profession of faith, and outward communion with the church of God, is not sufficient unto salvation, unless we lead an incorrupt life correspondent to the same, doing the thing which is right, and speaking the truth in our heart. And, therefore, the silly Papist is exceedingly deceived in relying so much upon the church's outside, to wit, upon the succession of Roman bishops, upon the multitude of Roman Catholics, upon the power and pomp of the Roman synagogue, crying as the Jews in old time, "The temple of the Lord, the temple of the Lord," our church is the temple of the Lord. The carnal and careless gospeller is deceived also, placing all his religion in the formal observation of outward service, for a mere verbal Christian is a real atheist, according to that of Paul (Titus 1:16), "In word they profess that they know God, but in their works they deny him;" and so many who seem to sojourn in God's tabernacle for a time, shall never rest upon his "holy hill;" and this assertion is expressly confirmed by Christ himself: "Not every one (saith he) that saith unto me, Lord, Lord, shall enter into the kingdom of heaven; but he that doeth the will of my Father which is in heaven. Many will say to me in that day, Lord, Lord, have we not prophesied in thy name? and in thy name have cast out devils? and in thy name done many wonderful works? And then will I profess unto them, I never knew you: depart from me, ye that work iniquity." Matthew 7:21-23. Consider this, all ye which are Christians in lip only but not in life, making a mask of religion, or rather a very vizard, with eyes, and mouth, and nose, fairly painted and proportioned to all pretenses and purposes. O think on this, all ye that forget God, he that dwelleth on high, and beholds the things here below, suffers none to rest upon the mountain of his holiness but such as walk uprightly, doing that which is just, and speaking that which is true. John Boys.