To further elaborate on my last post. If one defines "holiness" as keeping the commandments of God, one shows they seriously misunderstand what holiness is. Why? Because such a definition does not start with God. If holiness is to be understood, it must be understood in relation to how God "is" holy. Is God holy because God obeys Himself and loves Himself? Obviously not.
The issue of holiness is the issue of "otherness." God is "entirely other" as Art Katz was fond of saying. And it is the essence of this "otherness" that makes God holy. It's something God is in and of Himself. We are speaking something about his "ontological" being. Holiness is the issue of God's very nature. It's "what" He is. And as a result of God being "holy," God acts out that holiness. A. W. Tozer was right to pin-point holiness as the chief characteristic of God out of which all other characteristics flowed.
And it is from this that we must understand personal holiness. Unless we understand personal holiness from who God is, then we are bound to enter into false notions that holiness is about keeping God's commandments. A performance based understanding of holiness is not in keeping with Scripture. We are called to "be holy as I am holy." Thus, since God by nature is holy other, we too are likewise called to be by nature, holy other. And we can only receive such when we have undergone this inward change of nature, whereby God makes us holy by means of the grace given to us through the new birth. In this, we "become" holy and other.
You see, when we were justified by God, we were sanctified and "set apart" from the rest of the sinful race of Adam. Instead of being men who were dead, we were set apart as men who were made alive. Instead of being enslaved to this fallen demonic world, we were raised up with Jesus Christ and made to sit in heavenly places with Him through the spiritual union we have in Him. These acts of God towards us have "made" us holy.
As a result of being made holy by the Lord, we act as the Lord acts. The Lord is holy, therefore, everything He does is in keeping with who He is by nature. Likewise, we have been made holy, therefore, everything we are to do ought to likewise be in keeping with who we have been made by nature. We are not holy because of what we do, rather, we are holy because of who we are. And that holiness of character will ultimately manifest itself in our very conduct, as we joyfully love God, and keep His commandments. We are not doing these things to become holy, rather we do these things because we are holy.