As I pastor, I often speak of holiness as "Perfect Communion with God." Many of us (I would imagine most of us) have at one point experienced even a brief moment in time when we have been in perfect communion with God. During that moment, we are resting in His presence, in the knowledge that He has forgiven us of our sins, and we are in tune with His Spirit, hearing His voice and seeking His face. For some, that moment is in private worship, for others it is at an altar, or perhaps during a time of corporate singing.
In any case, as I explain it, the concept of holiness or Entire Sanctification is the extension of that moment. Instead of just one brief instant of "perfect communion" we "Practice the Presence of God" in order that we begin to live our lives in "perfect communion with God."
Holiness is not about what we do, but about the Sanctifying Grace of God, and the work of the Holy Spirit within us. As with all other elements of Christianity, God--through His grace--initiates, and we--through our faith (which is given to us by God's grace)--respond. Divine-human participation means that God initiates, but the human must respond.
God desires for each one to be holy. To be pure. To be mature. To be in pefect communion with Him. It is our responsibility to seek sanctification, that we would be constantly filled with His Spirit. But it is always His work of holiness within us, through His spirit.
Grace and Peace,
WJ