Building a community associated with the idea that a cord of three strands is not easily broken. Ecclesiastes 4:12
What is Holiness? Santification?
You see we (Christians) believe that we become the person we are as a culmination of all the decisions we have made 
as a response to the environment we've lived in. And as Christians we believe that environment includes a Presence (God) that non-believers don't acknowledge. I just paraphrased Acts 17:28, "for in God, we live, move and have our being."
So what this means to me is that we have moved God to the center (the most important part) of our environment. In this way God affects our entire environment and our environment affects Him. We sometimes forget that we can have an affect on God – not that we are equal to God but that God enjoys a give-and-take relationship with us. But unfortunately this is not what most people view as holiness/sanctification.
There are several variations on the definition of holiness:
1. Holiness as Rules and Regulations
a. This just means that people see holiness as a set of rules and regulations given by God and they need to keep them in order to be sanctified. Kind of a neat idea but not very practical – especially if we look at the "Holiness Code" as expressed in Leviticus chapters 17-26. The problem with this view is that holiness tends toward legalism and keeping the rules becomes the goal. Also, it's not very satisfying to keep the rules and if you read those chapters not very relevant to today.
2. Holiness as Purity
a. I think of Paul in 2 Corinthians 7:1 when he says "cleanse yourselves from every defilement of body and of spirit, making holiness perfect in the fear of God." But if we think about trying to keep pure we find ourselves right back into the problems of #1. We would focus more on avoiding sin rather that doing good, which would tend to make us isolated rather than insulated from the world. Not a good place to be.
3. Holiness as Being Set Apart
a. This is where most Christians focus their attention when talking about holiness or sanctification. While is important for us to understand this concept it still leads to some issues; first, we need to realize that we are separate and different but think about the attitude that could develop when we exclude "them" from us – not good, second, being different just to be different isn't very satisfying.
4. Holiness as Total Commitment
a. Boy if this could only be true – "wholly devoted to you!" is what we sing of or if you watch the mini-series The Stand, you hear a guy say "my life for yours!" But if you think about it this is kind of a vague notion, whose view of God are we talking about? How many crimes and bad deeds have been committed in the name of devotion to a deity? Too many to list here that's for sure! Commitment is a vital thing but we need some practical characteristics of that devotion so that we can live it out.
5. Holiness as Perfection
a. Wish I had a nickel every time I heard this one. We quote Matthew 5:48, "Be perfect, even as your Father in heaven is perfect." Our denomination is known for talking about perfection in this lifetime and we are always trying (unsuccessfully many times) to clarify the process. The problem is in the definition of perfection.
i. Some equate it with a lack of change – if holiness means a lack of change then we are in trouble because we are in a constant state of change
ii. Other times I've defined the term as being fit for a purpose – but this leads to problems because almost anything can be perfect – Atheists can be holy as long as they fulfill their purpose as atheists! Yikes!
iii. Then I've used the thought that perfection is being in a state as never having sinned. But since God is only perfect in this sense, it is hard for humans to be seen in this light.
6. Holiness as Christ-likeness
a. I personally like this definition – who doesn't want to be more like Christ? But alas this is a bad definition as well because it doesn't tell us what to imitate. How would you feel if I came in one Sunday morning and turned over every table in the church that had money on it!? I'm just imitating Christ!
What I'm coming to see holiness/sanctification is that it is a function of love. Love provides holiness with the foundation it needs to stand as a definition of holiness. In three little words, "God is love," (John 4:8) we see the heart of this definition. Love fulfills the intent of the biblical moral codes and rules. When we love, we act in a morally pure fashion, and purity is a consequence of love. Christians are to be totally committed to a loving God and to responding appropriately to God's call of love. Being Christ-like means living lives of love. Being set apart is best understood as having to do with love, because those who choose love distinguish themselves as a community that seeks to promote well-being. And holiness as perfection is understandable when perfection is characterized as living in love. When we love we bear witness to our sanctification.
We imitate God's love when we live in ways that bring abundant life to creation. Some of the most common expressions of love are actions such as forgiving, offering words of encouragement, donating money to the needy, displaying self-control, showing humility, trusting, respecting, showing compassion, telling the truth, being patient, liberating the captive and oppressed, and being kind.
The relations we have with others – especially our relation with God – largely determine what counts as love at any particular moment. God's prevenient grace sets the stage for our responses, because God acts first to offer us abundant life. In terms of relational holiness, we say that God relates to us by acting first in every moment to provide us with opportunities for free action. Those opportunities arise out of God's own actions, the actions of others, and our own previous actions. The relations we have with God and others set the context for each moment of our lives. God's moment-by-moment call requires us to respond. God calls us to love according to these multi-layered relations in which we live. Among all the possible actions, God encourages us to choose the one which promotes well-being.
When we choose the best to which God calls in any particular moment, we act in holiness. In that moment, we are "perfect as [our] Father in heaven is perfect." The ongoing life of loving God, others, and God's creation, including ourselves, is the life of holiness.