Holiness is a much-misunderstood concept. It conjures up images of solitary hermits shutting themselves away from the distractions (and also the needs) of the world, or of self-righteous Pharisees condemning lesser mortals for their failures (Luke 18:11,12).
But Biblical holiness is not a subjective aura of saintliness, and it certainly does not involve withdrawal from the secular world. It simply means living in a way that honours God. He has called us out of the world to make us His own special people, and it is only by being distinct from the world that we can fulfil His purpose for us. So instead of conforming to the values and standards of the world, our lives must reflect the character of the God we belong to. “Just as He who called you is holy, so be holy in all you do; for it is written: ‘Be holy, because I am holy.’” (I Peter 1:14,15) Peter is writing to Christians, but he quotes from the beginning of Leviticus 19 – which is a manual of holiness.
Leviticus 19 is an interesting chapter to read. It consists of a wide-ranging and apparently random list of commands, some of which appear rather obscure to us (why the ban on mixed fibres, or on certain hairstyles?); but it is clearly based on the Ten Commandments, which it fleshes out with numerous practical examples taken from all aspects of everyday life. The words “I am the LORD your God” run like a refrain throughout. It is because God ‘is who He is’ that the Israelites had to live in this way – and we shouldn’t need any other explanation or incentive to obey Him. The centrepiece of the chapter is one of the two ‘great commandments’ of Jesus: “Love your neighbour as yourself” (Leviticus 19:18; Mark 12:29-31). If we obey this one commandment, we shall automatically fulfil all the others (Galatians 5:14; Romans 13:10).
So does living a holy life merely involve loving one’s neighbour? There’s a little more to it than that. God told the Israelites, “Consecrate yourselves and be holy, because I am the LORD your God. Keep My decrees and follow them. I am the LORD, who makes you holy” (Leviticus 20:7,8). And Jesus said something very similar to His disciples: “Anyone who loves Me will obey My teaching. My Father will love them, and We will come to them and make Our home with them” (John 14:23). Obedience is only part of the equation. The process of sanctification (‘making holy’) is a virtuous circle, which is set in motion when God chooses us for Himself. It is then our responsibility to make ourselves worthy of His call, by conforming our lives to His will. But as we set out to obey God’s commands, He makes us holy by filling our lives more and more with His presence. So holy living cannot be reduced to sterile rule-keeping; at its essence, holiness is a deepening relationship with God.