This is a key verse in Leviticus, a book that has much to say about holiness. It raises the bar above what’s gone before and sets an agenda that runs into eternity. It’s mankind’s greatest challenge, but by God’s power it shall be realised.
The Bible hardly mentions holiness before the Exodus and giving of the law, but from then on it’s the main objective: God is holy and He’s calling out a people for Himself to be holy as He is holy.
So what exactly is holiness? Essentially it’s defined by God – it’s to do with His qualities and is defined with reference to Him. There are two key elements: a sense of being separated and set apart from what is not holy, and a moral excellence that’s defined by God – He sets the standards. So the first place to look to understand holiness is to look at God Himself: He is awesomely other and morally perfect.
This, however, is a little hard for us to grasp, with our earth bound perspective. So when God gave this command He did so in the context of defining separation and moral excellence for the ancient Israelites. Looking at what He taught them is therefore a good place to start.
The first thing He did no longer applies to us in quite the same way. It’s one of the ways in which the Old Testament differs from the New. In the spiritual infancy of Old Testament times, God in His wisdom knew that His people needed to be literally separated off for their healthy development as a holy nation. He gave them their own land and various rules that would encourage a sense of being separate and different. This is the reason for laws like not wearing ‘“‘a garment made of two kinds of material’”’(Leviticus 19:19) and the various kosher food laws. This created space and a separation-identity for a society whose moral laws could model God’s ways. The moral laws still apply, and can teach us holiness in the morality sense, either as general principles derived from Israel’s specific historical national laws, or as personal moral teachings valid for all time. The separation laws changed with the New Testament/covenant/‘law’:-
This came with an outpouring of God’s Holy Spirit in a new way, such that God’s people are no longer morally corralled externally, but governed from within by the ‘law of the Spirit’(Romans 8:2). This Spirit driven motivation makes physical separation from the ‘world’ less necessary for moral distinctiveness – although the practice of ‘withdrawal’(Luke 5:16) for spiritual disciplines remains important.
Secondly, the branch of Jesse (Isaiah 11:1) had budded, ‘“a light for revelation to the nations, and the glory of your people Israel”’(Luke 2:32); the plan was going truly global. So God revealed to Peter that the food laws were abolished as ‘the gift of the Holy Spirit was also poured out on the Gentiles’(Acts 10:45), as had been God’s plan all along: ‘“I will make you a great nation… All of the families of the earth will be blessed”’(Genesis 12:2-3).
The coming of Christ was obviously the trigger for this development, and he teaches/models holiness for us in this new Spirit filled in-the-world sense. He was God, perfect in holiness, yet in the world as the perfect ‘“light of the world. He who follows me… will have the light of life.”’(John 8:12). If we want to know what holiness is, although we can be helped by contemplating God the Father and studying His Old Testament laws, we can see it perfectly lived out in our world by Jesus, and receive power to grow in holiness by His Holy Spirit living in us.
Before we get too carried away though, this is a huge challenge. We’re still inherently sinful people living in a sinful world. We’re often far from holy, by negligence, weakness or our own deliberate fault, as a commonly used liturgy goes. The world might well accuse us of hypocrisy, not practising what we preach, but that’s the other half of what we preach: Obviously we will never achieve Jesus’ sinless holy perfection in this world, that’s why he came to die in our place.
However, we are now set-apart on a mission, as God’s holy people, cleansed by His blood, living and growing by His Spirit, spreading the good news of His Holy Kingdom. As Jesus said, ‘“This Good News of the Kingdom will be preached in the whole world for a testimony to all the nations, and then the end will come.”’(Matthew 24:14), and perfection in our eternal Holy Home begins…