Ans. This passage teaches us the very solemn truth that if we, by a false use of our liberty, embolden a weak brother to act against his conscience, we, so far as in us lies, cause him to perish, by destroying the action of his conscience toward God. It is of the utmost importance to allow Scripture to have its full play upon the soul, and not to blunt its edge by the dogmas of systematic divinity. It is a good thing to open all the chambers of the heart and have them ventilated by the pure air of Scripture. The same authority that says, "My sheep shall never perish," warns us against causing a weak brother to perish by a self-indulgent, uncharitable use of our liberty; and it will be our wisdom, as it most assuredly is for our moral security, to hearken to the one as well as to the other.
Ans. When a sinner has found out that he is lost, ruined and guilty, and sees that Christ died for him, then he is not only born again (that is, a new life in his soul), but he is also a child of God, and the Holy Spirit comes to dwell in him, and gives him the conscious knowledge that he is a child of God. This is what it means: The Spirit itself beareth witness with our spirit that we are the children of God, so I do not doubt it at all. Faith does not look for feelings, but just rests on the Word of God. (See also Gal. 4:66And because ye are sons, God hath sent forth the Spirit of his Son into your hearts, crying, Abba, Father. (Galatians 4:6).)