He taught us new ways of relating to God. Firstly, in Himself He showed us a God who, while losing nothing of His divinity, was nonetheless like us in all ways except sin - including the capacity for suffering and death.
Secondly He taught us to call God ‘Abba’ (‘Daddy’), and gave us the image of the Prodigal Son’s father. As one of my priests is fond of saying, the story should really be called ‘the Prodigal Father’ instead (prodigal meaning excessively generous and spendthrift), in view of the father’s unbounded and free mercy and generosity. It’s a radical shift from previous views of God as more of a stern, impersonal and harsh judge.