1 John 3:7-10 / John 1:35-42
Generally speaking, the issues of life are not distinctly clearly black and white. If it is so then decisions are easy to make as the matter is clearly divided between black and white.
But as it is, life is a mixture of black and white and hence grey areas abound in areas like bioethics, sexuality, morality, etc.
But when it comes to the spiritual life, that is not the case at all. Because between good and evil, it is mutually exclusive and that good and evil cannot co-exist in one entity.
As the 1st reading puts it: to live a holy life is to be holy just as God is holy; to lead a sinful life is to belong to the devil.
And this is how the children of God are distinguished from the children of the devil - anybody not living a holy life and not loving his brother is no child of God's.
In other words, we can't be children of God and at the same time the children of the devil. It is either one or the other. There is no grey area in this matter.
And we shouldn't be giving ourselves concessions or excuses that we are weak and a bit of sin is alright because it was to undo all the devil had done that Jesus came to save us and to restore our dignity as children of God.
As we continue to celebrate the Christmas season, let us remember that God became man so that man can become like God.
God is holy. If we are to be children of God then we too must strive to be holy. There can be no grey area about this.