Achintya-bhedabheda-tattva refers to the inconceivable oneness and difference of the Supreme Person and His energies. This is one of the key points of theistic philosophy taught by Chaitanya Mahaprabhu. As parts of God’s energy, we’re also equal in quality with God, but there’s a vast difference in quantity. We’re each infinitesimal sparks of spiritual energy, and the Supreme Person, Krishna, is the infinite, supreme source of all energies.
Some parts of the Vedas say that all beings are one with God, and others say that God is different from all beings. Vedanta philosophers have long argued back and forth about this, but Chaitanya Mahaprabhu taught that both statements are simultaneously true.