“Blessed are the pure in heart, for they will witness God.”

(Matthew 5:8)

What does it mean that the pure in heart will “see” or “witness” God? Does it mean that they will visibly witness God in this life as Moses did from behind (Exodus 34:5-7) or as Manoah did when the birth of Samson was announced (Judges 13:22)? Does it mean that we will “dream dreams and see visions”? A better understanding of what Jesus is speaking, that applies not only to believers across the ages but also to the church across the age, is that they will see the hand of God at work. While God has appeared before people at specific times and places in human history, such theophanies should not be understood as a normative experience. What is normative, though, is the believer’s capacity to see the providential work of God unfolding in his life as well as in his church.

If we wish to see (with understanding) God’s hand at work, Jesus tells us that we must be pure in heart. Yet, what is this purity? Indeed, we are all sinners, every last one of us, so how can we ever be truly clean in this context? For the Christian, our cleanliness is not our own, but is an alien cleanliness as we stand before God clothed in the righteousness of Jesus (2 Corinthians 5:21) and eternally, our robes will be washed in the blood of the Lamb (Revelation 7:14). Yet, what of the corporate church? How does it establish and maintain its purity?

The word that is translated here as “pure” is the Greek word καθαρός (katharos). As a term it can refer to that which is pure or, more narrowly, that which is free from contaminants. One of the easiest illustrations of purity and contamination is something that we all use on a daily basis: water. Sometimes, when water is contaminated, the contamination is easily detected. There might be dirt, bits of plant material, etc… that are visible within the water itself. At other times, contamination is a little more difficult to detect. The water may look clear but smell a little funny or it may have unhealthy bacteria that is invisible to the eye but also harmful to the body. In such cases, things like charcoal filtration or distillation may be necessary to make the water healthy.

When applying this kind of analogy to the church, it should be obvious how easily contamination can enter into the life and worship of the body. Sometimes it is obvious and visible, for instance, when churches establish imagery of God, breaking the second commandment or when they harbor adulterous sins amongst their membership. Some are more subtle, like preaching “self-help” sermons that teach you how to “live your best life now” or practice worship with man-made songs instead of with the psalms that the Lord has given to His people for the purpose of worship. The Westminster Confession, chapter 21 speaks of those elements that are Biblically commanded of God’s people: prayer, reading of the Scriptures with godly fear, sound preaching of those Scriptures as well as hearing with application to the soul, singing psalms with grace in your heart, offering and receiving sacraments as instituted by Christ, and other oaths, vows, fastings, and thanksgivings upon special occasions. The Belgic Confession, Article 29 narrows this down to three marks: the pure doctrine of the Gospel is preached, the sacraments as instituted by Christ are maintained, and that church discipline is exercised to constrain sin.

When we start adding in “other things” based on our preferences, we see the purity of the church contaminated. When the church pursues preference, feelings, or personal agendas, it ceases to be the True Church and its worship is something akin to that of Nadab and Abihu. They may seem to have fire, but it is an alien fire that God will not bless. And, in turn, such churches will no longer witness God and His power, but they will become witnesses of themselves and promoters of their own power and influence over men. Purity, dear Christian, in worship and practice, is important to God according to His Word.