Holy Trinity
The Christian doctrine of the Trinity holds that God is one God, but three coeternal consubstantial persons or hypostases - the Father, the Son (Jesus Christ), and the Holy Spirit - as "one God in three Divine Persons". The three Persons are distinct, yet are one "substance, essence or nature" (homoousios). In this context, a "nature" is what one is, whereas a "person" is who one is.