"These are .. sown on good ground; .. and bring forth fruit". Mk. 4:20

Is holiness an evidence that someone has a clean heart, a new mind, and that this person is indeed a Christian? I have been discussing this, and some would say no, that holiness isn't evidence, but only faith can be the evidence of ones regenerated spirit.

I understand that some people may look and act holy, and yet are not Christians, but that doesn't change the fact that Christians will live a holy life, and this will show forth in the overall conduct.

This conduct is according to the grace of God alone, through faith in His promise, that He will work in us to will and to do His will, so that we bear fruit of holiness. He will bear other fruit as well; fruit of love, peace, joy, goodness, self-control, gentleness, kindness, mercy, godliness, and faith.

It's the Holy Spirit who waters the soils of our hearts to bear this fruit, and so He brings this forth for the sake of the Gospel, and for the glory of the Father.

I believe there has to be holiness in a believers walk as a partial evidence of his genuinely being converted.
Righteousness & love undergirded by faith, undergirded by His grace and power, are the salt and light that the Christian produces in his, or hers, life. And this life of faith is established upon the rock, a solid foundation; not the sand, where the faith built here will one day have a great fall. (Matt. 7)

Are there days when I don't look like a Christain? To be honest, I would say there may even be seasons when I am not walking in the Spirit of love and truth as I should, but God is trustworthy & faithful to His own. Our Father knows how to discipline His children a lot better than we know how to discipline our own children, and He will not forsake us.

And that's a very good thing to understand, a true blessing for the child of the Lord, for if you're not being discipined, then you are not His child, and that's a bad place to be.