I have just finished editing an interesting article on ‘St Thomas Aquinas on Eucharistic Ecstasy’. At one point the author quotes Dom Sebastian Moore thus: ‘“I am” equals “I love”. “I love” is the only way to say “I am”.’
From there it is just a short step to a Christian counterstatement to Descartes’ Cogito. In contrast to the rationalistic individualism of ‘I think, therefore I am’, the Christian says ‘I am loved, therefore I am’ (therefore I love).