"I am the Lord your God; consecrate yourselves and be holy, because I am holy." Leviticus 11:44
I have always known that God is holy; it's a fact that I know and accept without question. According to the scripture above, I'm suppose to be holy also.
I have never thought of myself as holy. Holiness seems like a very lofty goal --- definitely a high standard, but God wants His people to be holy just as He is holy. (Ephesians 4:24)
Holy means set apart for a sacred use. Something that is holy is different and unique. This is how God views Christians --- we are separate from the world and we have a special purpose.
Our actions and attitudes should be different than non-Christians since we should be reflect the goodness of Jesus Christ. Remaining spiritually separate from the world is not easy to do living in a world that is unholy.
We cannot achieve holiness by ourselves; holiness begins with faith in Jesus. Through Jesus' death, He will "present you holy in His sight, without blemish and free from accusation." (Colossians 1:22) By trusting in Jesus, our sins are forgiven, we are made right with God and we are empowered to live a holy life.
I have been holy for a long time now (ever since I became a Christian as a child). I just haven't had God's perspective when looking at myself. I tend to be critical of myself which means my view of myself tends to be negative. When God looks at me, he sees me as holy and as His child; He sees me in a positive light. I need to change the way that I look at myself and see myself as God sees me, and I need to remember that I am holy and act accordingly (all of this with God's help, of course!).
*Colossians 3 contains rules for holy living.