by Thomas Watson
“Blessed are the pure in heart, for they shall see God.” (v.8)
“Blessed are the poor in spirit, for theirs is the kingdom of heaven.”
“Blessed are those who mourn, for they shall be comforted.”
“Blessed are the meek, for they shall inherit the earth.”
“Blessed are those who hunger and thirst for righteousness, for they shall be satisfied.”
“Blessed are the merciful, for they shall receive mercy.”
“Blessed are the pure in heart, for they shall see God.”
“Blessed are the peacemakers, for they shall be called sons of God.”
“Blessed are those who are persecuted, for theirs is the kingdom of heaven”
1. The REASONS for purity.
 Purity is a thing called for in Scripture. ‘Be holy for I am holy’ (1 Peter 1:16). It is not only the minister bids you be holy—but God himself calls for it. What would the Holy God do with unholy servants?
 Because of that filthy and cursed condition we are in, before purity is wrought in us. We are a lump of clay and sin mingled together! Sin not only blinds us—but defiles us. It is called filthiness (James 1:21). And to show how befilthying a thing it is, it is compared to a plague of the heart (1 Kings 8:38), to corruption (Deuteronomy 32:5), to vomit (2 Peter 2:22), to infants ‘helplessly kicking about in their own blood’ (Ezekiel 16:6), and to a ‘menstrual cloth’ (Isaiah 30:22), which (as Jerome says) was the most defiling thing under the law. All the legal warnings which God appointed, were but to put men in mind of their loathsomeness before they were washed in the blood of Christ. If all the evils in the world were put together and their quintessence strained out, they could not make a thing so black and polluted as sin does! A sinner is a devil in a man’s shape! When Moses’ rod was turned into a serpent, he fled from it. Would God open men’s eyes and show them their deformities and damnable spots—they would fly from themselves, as from serpents! This shows what need we have of purity. When grace comes—it washes off this hellish filth. It makes Ethiopians into true Israelites! It turns ravens into swans! It makes those who are as black as hell—to become as white as snow!
 Because none but the pure in heart are savingly interested in the covenant of grace. Covenanted people have ‘the sprinkling with clean water’ (Ezekiel 36:25). Now, until we are thus sprinkled, we have nothing to do with either the new covenant, or with the new Jerusalem. If a will is made only to such people as are so qualified, none can come in for a share—but such as have those qualifications. Just so, God has made a will and covenant that he will be our God, and will settle eternal glory upon us—but with this clause or proviso in the will—that we be purified people, having the ‘clean water sprinkled, upon us. Now until then, we have nothing to do with God or mercy.
 Purity is the end of our election. ‘He has chosen us—that we should be holy’ (Ephesians 1:4). Not for holiness—but to holiness. ‘Whom he did foreknow, he also did predestinate to be conformed to the image of his Son’ (Romans 8:29). God predestinates us to Christ’s image, which image consists ‘in righteousness and true holiness’ (Ephesians 4:24). So that until you are holy, you cannot show any sign of election upon you—but rather the devil’s brand-mark!
 Purity is the end of our redemption. If we could have gone to heaven in our sins, Christ needed not have died. Why did he shed his blood, but to redeem us from an ’empty way of life’? (1 Peter 1:18, 19). ‘Christ gave himself for us to redeem us from all wickedness and to purify for himself a people that are his very own’ (Titus 2:14). Christ shed his blood—to wash off our filth! The cross was both an altar and a laver. Jesus died not only to save us from wrath (1 Thessalonians 1:10)—but to save us from sin (Matthew 1:21). Out of his side came water which signifies our cleansing, as well as blood which signifies our justifying (1 John 5:6). The truth is, it would make Christ monstrous, if the head should be pure and not the members.
2. Why purity must be chiefly in the heart.
 Because if the heart is not pure, we differ nothing from a Pharisaic purity. The Pharisees’ holiness consisted chiefly in externals. Theirs was an outside purity. They never minded the inside of the heart. ‘Woe unto you, scribes and Pharisees, hypocrites! You are so careful to clean the outside of the cup and the dish, but inside you are filthy—full of greed and self-indulgence! Hypocrites! You are like whitewashed tombs—beautiful on the outside but filled on the inside with dead people’s bones and all sorts of impurity!’ (Matthew 23:25, 27). The Pharisees were good only on the surface. They were whited-over, not white. They were like a rotten post overlaid with fine paint. They were like a gold chimney—but within nothing but soot. Of such hypocrites Salvian complains, who had Christ in their mouths—but not in their lives.
We must go further. Be ‘pure in heart’, like the king’s daughter ‘all glorious within’ (Psalm 45:13); else ours is but a Pharisaic purity; and Christ says, ‘For I tell you that unless your righteousness surpasses that of the Pharisees and the teachers of the law, you will certainly not enter the kingdom of heaven.’ (Matthew 5:20).
 The heart must especially be kept pure, because the heart is the chief seat or place of God’s residence. God dwells in the heart. He takes up the heart for his own lodging (Isaiah 57:15; Ephesians 3:17), therefore it must be pure and holy. A king’s palace must be kept from defilement, and especially his throne. How holy ought that to be! If the body is the temple of the Holy Spirit (1 Corinthians 6:19), the heart is the holy of holies! Oh take heed of defiling the room where God chiefly dwells! Let that room be washed with holy tears.
 The heart must especially be pure, because it is the heart which sanctifies all that we do. If the heart is holy, all is holy—our affections holy, our duties holy. ‘The altar sanctifies the gift’ (Matthew 23:19). The heart is the altar that sanctifies the offering. The Romans kept their springs from being poisoned. The heart is the spring of all our actions; let us keep this spring from poison. Be ‘pure in heart’.
See here what that beauty is, which beautifies a soul in God’s eye, namely, purity of heart. You are but a spiritual leper—until you are pure in heart. God is in love with the pure heart, for he sees his own picture drawn there.
Holiness is the angels’ glory. They are pure virgin-spirits. Take away purity from an angel—and he is but a devil! You who are pure in heart—have the angels’ glory shining in you. You have the embroidery and workmanship of the Holy Spirit upon you.
The pure heart is God’s paradise where he delights to walk. It is his lesser heaven. The dove delights in the purest air. The Holy Spirit who descended in the likeness of a dove, delights in the purest soul. God says of the pure in heart, as of Zion, ‘This is my rest forever, here will I dwell’ (Psalm 132:14). God loves the loveliest complexion. The pure in heart is Christ’s bride, decked and bespangled with the jewels of holiness. ‘You have ravished my heart with one of your eyes’ (Canticles 4:9). Your eyes, that is, your graces; these as a chain of diamonds, have drawn my heart to you. Of all hearts God loves the pure heart best. You who dress yourself by the looking-glass of the Word and adorn ‘the hidden person of your heart’ (1 Peter 3:4), are most precious in God’s eyes, though you may be as bleary-eyed as Leah, or as lame as Barzillai. Yet being ‘pure in heart, you are the mirror of beauty and may say ‘Yet shall I be glorious in the eyes of the Lord’ (Isaiah 49:5). How may this raise the esteem of purity! This is a beauty which never fades and which makes God himself fall in love with us.
If we must be pure in heart—then we must not rest in outward purity. Morality is not sufficient. A swine may be washed—yet a swine still. Morality does but wash a man, grace changes him. Morality may shine in the eyes of the world—but it differs as much from purity, as a pebble differs from the diamond. Morality is but strewing flowers on a dead corpse. A man who is but highly moral—is but a tame devil. How many have made ‘morality’ their Savior! Morality will damn, as well as heinous vice. A boat may be sunk with gold, as well as with dung.
Observe two things:
1. The moral person, though he will not commit gross sins—yet he is not sensible of heart sins. He does not discern the ‘law in his members’ (Romans 7:23). He is not troubled for unbelief, hardness of heart, vanity of thoughts. He abhors gaol-sins, not gospel-sins.
2. The moral person rises against holiness. The snake has a fine appearance—but has a deadly sting. The moral man is fair to look to—but has a secret antipathy against the holy ways of God. He hates grace, as much as vice. Zeal is as odious to him as uncleanness. Morality is not to be rested in. The heart must be pure. God would have Aaron wash the inner parts of the sacrifice (Leviticus 9:14). Morality d