I will write my law on their hearts.

Christ, like a grain of wheat that dies in order to produce new life, dies for us.
Following, his example, we are called to realise that if we want eternal life we have to be prepared to give our lives to God. The Lord writes his law in our hearts and we submit humbly to his will, even in times of pain and suffering. There is no greater school in which to grow in holiness.