Discover God's love and grace through the discipline of his people.
The book of Isaiah has many words about God's anger and his judgement of his people. Why read a book about anger and judgement? Because God's words of judgement are still words of grace. He has not completely abandoned his people, for he is still speaking to them! God shows his grace by speaking honestly to them (and to us), telling his people how far they have placed themselves from him. Yet he does this so they (and we) will draw near.
And these are words of grace because they help God's people make sense of their situation. When Isaiah writes, some of God's people have already been exiled while others face exile to come. In that setting, it is easy to wonder if the Lord has completely cut ties with them. The words of judgment show he has not.
So as painful as these words of punishment sound, we should hear them today. Our God wants a relationship with us, but he will not share us with other gods. He calls us to return to him alone. We are his beloved children, but the Lord alone is our Father and Mother.
