In his homily for Mass celebrated at the Santa Marta residence Monday Pope Francis warned against the harm of “lukewarm” Christianity, calling on faithful instead to be “children of light.” The Lord has strong words towards Christian who avoid overstating their Christianity, the Pope told the congregation on Oct. 27. Such Christians do great harm “because their Christian witness is a witness which ultimately disseminates confusion, disseminates a negative witness.” At the End Times, the Pope continued, the Lord will say to these “gray” Christians: “You are neither hot nor cold. If only you were hot or cold. But because you are lukewarm — therefore gray — I vomit you from my mouth'.” Contrasting lukewarm Christians with the “children of light” and the “children of darkness,” the Holy Father described these “gray” Christians as going from one side to the other, making it difficult to determine whether they follow God or the devil. “They are always lukewarm,” he said. “They are neither luminous nor dark.” Pope Francis turned his reflection to the day's first reading from Saint Paul, calling on Christians to be children of light, rather than children of darkness. In order to know which sort of children we are, the Pope said, we should consider whether the words we use fall into one of four categories: hypocritical, empty, frivolous, or obscene.   Such words, he said, are not used by “the children of light. They are not from the Holy Spirit. They are not from Jesus, they are not the words of the Gospel. . . this way of speaking, always speaking of filthy things, or frivolously, or empty, or speaking hypocritically.” Instead, the Holy Father said, citing Saint Paul, we are called to imitate God by walking in charity, goodness, and gentleness. “Therefore, be imitators of God and walk in charity. And this is the word of a child of light.” “There are luminous Christians, full of light,” the Pope said, “who seek to serve the Lord with this light.” He added that there are “dark” Christians “who lead a life of sin, a life far from the Lord.” Warning against being deceived by statements which are “beautiful, well said, but empty,” Pope Francis challenged Christians to ask themselves: “Am I a Christian of light? Am I a Christian of darkness? Am I a Christian of gray?” In this way, he said, we can “take a step forward toward an encounter with the Lord.”