All Christians are called to a life of discipleship which helps to extend Jesus' work and presence in the world.
As Saint Teresa of Avila states:
Christ has no body now on the earth but yours, no hands but yours, no feet but yours. Yours are the eyes through which Christ’s compassion is to look out to the world. Yours are the feet with which Christ is to go about doing good. Yours are the hands with which Christ is to bless all people now.