The Force of the Expressions “in Christ” and “in the Lord”? Marriage “Only in the Lord”?

Question: What do you consider the force of the two expressions, “in Christ,” and “in the Lord”? 2. What means, as said of marriage, “only in the Lord” (1 Cor. 7:39)? G. B. E.
Answer: Though they approach nearly, there is a shade of difference, the first rather expressing privilege, the latter responsibility. 2. This is certainly so in the case proposed. Two persons might be “in Christ,” truly attached in affection, but the one entering into the full relationship of the Christian, the other hardly rising in faith or practice above a simple believer, content with remission of sins and general care as to moral walk, and in a false position ecclesiastically. Would it be “in the Lord” for such to marry? Can two walk together before Him who are not agreed in a duty so important for His glory?