In this text unbelief in Christ is represented as a positive crime a crime with which, in point of enormity, no other form of human sinfulness can be compared a crime which not only fastens upon its subject the guilt, and binds him over to the penalty of all his other sins, but which is itself the fullest and most striking development of enmity against God and opposition to His government which can possibly be presented.
I. Note the new circumstances and position in which the Gospel of Christ places every one of its subjects. We are here upon trial for an eternal world. Pardon is offered to us as a free gift from Him who has magnified the law and made it honourable; and everything now turns upon simple faith in Jesus Christ, upon an accordance with God's plan of forgiveness, a cordial acquiescence in the principles upon which that forgiveness is offered. Now the language addressed to us is not "He that doeth these things shall live by them," but "He that believeth shall be saved."
II. It goes not a little way to aggravate the guilt of the unbeliever, that God has been pleased in His Gospel not only to state the plan through which He forgives sin, but to show also the indispensable necessity of that plan as growing out of His justice as God, and His uprightness as a moral governor. He tells us in language too plain to be misunderstood, that He can save us in no other way than through faith in His Son. The a sacrifice of Jesus Christ was a method of infinite wisdom to pay tribute of justice, while it threw the mantle of mercy over the lost.
III. The Gospel of Jesus Christ, which unbelief rejects, is the highest expression which God could give us of His grace. Unbelief stands by itself, perfectly isolated in the features of enormity which mark it as least of all sins allowing of an apology or admitting of defence. It is not a sin of ignorance, for every man under the light of truth knows it to be wrong. The convictions of his own spirit clear, numerous, and irrepressible often testify against him as one who sins against light and knowledge.
E. Mason, A Pastor's Legacy,p. 80.
References: John 3:18. Spurgeon, Sermons,vol. vii., Nos. 361, 362; Ibid.,vol. xvi., No. 964.