The Madan Mohan deity is the sambandh deity. Sambandha means our relationship with Krishna. Lord Caitanya began His teachings to Sanatana Goswami with this simple principle –
jivera swarupa hoya krishnera nitya dasa.
We are not this body; we are the eternal soul. Qualitatively, we are non-different from Krishna, but quantitatively Krishna is the complete whole and we are just an infinitesimal part. We are all eternally the servant of the servant of the servant of the Lord. Inherent within the heart of every living being, is love for Krishna, and the highest dharma is to awaken that love of God within our heart. To understand Krishna as the ultimate object of our love and our seva is the beginning of true Bhakti.