I am currently taking a course through Nazarene Bible College regarding the history of the Church of the Nazarene, and one of the discussion topics that has come up recently is our doctrine of sanctification. What is it? How do you know if someone is sanctified?
It doesn't have to be as complicated or theological as we sometimes make it. As someone in my class put it, when you accept Jesus for the first time you give him your sin, and when you are sanctified you give him your life. Christians are sanctified when they ask for God's precious gift of the Holy Spirit. Only when we fully accept this gift are we entirely sanctified. It all comes down to being completely sold out for Jesus and being filled with the power of the Holy Spirit.
Another question came up about whether or not you can tell if someone is sanctified, which is a tough question. Some students thought that it should be obvious if someone is sanctified, because their lives would be considerably different than people of the world. I tend to agree, as I have seen people who are filled with the Holy Spirit and joy just seems to flow from them that makes them different in a very intriguing way. Asking for the power and strength from God's Holy Spirit is a daily thing for me, and I think it's important for all of us Christians to do. Imagine what God could and would do with a church full of sanctified Christians. Their communities wouldn't know what hit them.