"If we are “out of our mind,” as some say, it is for God; if we are in our right mind, it is for you.”
2 Corinthians 5:13 NIV
When we live with Christ as the focus our decisions and thoughts may not make sense to those around us. The world often takes a very different stance to that of Christ.
For many the grace of God is ludicrous, it doesn't make sense. To many, those of us who recognise that we can do nothing to earn our way to God, will appear to be "out of our mind".
Christ defines redemption, forgiveness, acceptance and the beauty of a second chance (only, in His abundance He goes above and beyond in giving endless chances). This is Grace; it is counter-cultural to the world we live in. But, with God's power within us, we have the choice to operate in Grace. We have a resource which is different to that of the world.
In this verse there is an urgency in what Paul says to the Corinthians, he has a boldness which he asigns to living for Christ. He is confidently "out of his mind" for Christ. When we allow the love and grace of God to permeate all of our thinking, we too can have this bold confidence to live the counter-cultural life to which Jesus has called us.