"Ubuntu," is a word Desmond Tutu describes as meaning, "my humanity is inextricably bound up in yours." It is also commonly described as a word with no counterpart in English. That's not true. There is a word, "coinherence," coined by the Christian mystic writer Charles Williams and explicated most especially in his "Theology of Romantic Love," which refers to "existing in essential relationship with another, as innate components of the other."
Although he coined the term, the idea itself is ancient, and central (though of course not unique) to Christian belief. In particular it is contained in all of these specifically Christian concepts: of the Trinity, of Christ's nature as both very Man and very God, of his presence in the Eucharist, and of the one body of the faithful (the communion of saints) which transcends time and space.
It is particularly present in Jesus' insistence that when we meet the sick, the troubled, the beggar at the door, we are actually meeting him, and as we do to them, so we do to him. In other words, "my humanity is inextricably bound up in yours."