Note 14 at Ro 5:7: Paul was attempting to explain the great love of God shown to us through grace. To illustrate it, he drew on the greatest expression of love known to man: laying down your life for another (Joh 15:13). However, Paul took it a step further.

It is possible to imagine people giving up their lives for others. That has happened many times. But it is inconceivable that they would sacrifice their lives for their enemies. Yet that was exactly what God did (Ro 5:10). Since this is so, how could we ever doubt God's goodness to us now? On our worst days as Christians, we love God infinitely more than our best days as unbelievers.