Images of baptism
"Whoever believes in me, as Scripture has said, rivers of living water will flow from within them.” John 7.38
In his treatise De Isaac Ambrose never refers to baptism explicitly but instead through a series of images. The amorous language of the Song of Solomon suggests the desire of the soul for intimate union with Christ. The kisses which the lovers in that poem exchange are passionate "kisses of the lips", as if pouring themselves into each other. This anticipates Jesus' promise to pour out the Spirit on those who believe. The notion of "pouring" points towards further images - of wells and fountains. Ambrose makes particular reference to the well at which Isaac and Rebecca meet (Genesis 24), the well where Jesus encounters the Samaritan woman (John 4) and the lovers tryst (Song of Solomon 4.15).
Ambrose finds in these images a progression akin to spiritual formation and appropriate to the preparation of candidates for baptism. Their role model is Isaac, who points towards Jesus in his qualities of modesty, humility and gentleness and in his detachment from worldly goods. The emphasis on individualistic progress and the apparent rejection of all things material may seem neoplatonic. But then Ambrose takes two unexpected turns. First he insists that rather than rejecting our physical and material selves, spiritual progress involves our re-integration as body and soul. And secondly, this does not happen in isolation but within the context of the church, which takes us back to the dual identity of Rebecca, representing both the individual and the church, as lover and bride of Christ.
So true humanity is found through identifying with Rebecca in her desire for Isaac, who points towards Jesus as the fulfilment of all our desires. Because God's love is personal yet inclusive, we are exhorted towards generosity in love - of God and neighbour. Ironically the route to contentment and fulfilment comes through shunning material comforts in order to restore the balance of self-control to the soul (or will) over our carnal appetites; not in order to reject the body but for the benefit of the whole person, body and soul together. This cannot be done in isolation - only by grace, through Christ, in the context of the church. Baptism is the sign of our re-birth as whole people in communion with the whole people of God.