Calvin
- 5:6
- The water and the blood refer to Christ's fulfillment of the OT types, and His abolishing of the OT Law [?]. The water being that which cleansed in preparation for God's presence, and the blood that which expiated our sins, and allowed reconciliation. The fact that Christ brings complete sanctification shows Him to be the Messiah of God. The reference to water and blood also reflects Christ's death, in which water and blood flowed from His side. This signified that He had fulfilled the types of cleansing and reconciliation seen in the OT rites. The truth of these things is testified to us by the Holy Spirit, who is truth.
- 5:7
- The verse is considered suspect, as many manuscripts don't contain it. However, if we assume it to be a valid part of Scripture, then its point is that as God is a Trinity, He calls to us in all three persons to have faith in His Son. Their 'oneness' in this case refers to their agreement in regards to Christ, not to their essence. The Spirit gets dual mention here inasmuch as He testifies both from Heaven, as God, and on earth - in our hearts.
- 5:8
- The water and the blood testify of Christ, in that they show in Him the fulfillment of the OT rites, He having accomplished completely what those rites could only accomplish in part. The Holy Spirit is a required third testimony, for without His testimony, we would still not see the truth of the other two. (Ro 1:4 - Jesus having been declared the Son of God still required the seal of the Holy Spirit for us to discern the truth.) Further, it is the Holy Spirit that applies the blood of Christ to our lives and makes it effective on our part. If the witness of three men is to be accepted as true, how much more so the triune witness of God - the Spirit concurring with the Law and the prophets? The whole purpose of Christ's coming was to cleanse us by His washing, and to reconcile us to God by His sacrifice. Although cleansing is also found in the reconciliation, it is mentioned as two, even as the Law regards them as two requirements. Thus, Christ came 'not only' with the water - not just the cleansing, or a partial answer - but also with the blood, bringing a complete answer in His redemption.
- 5:9
- It is only the corrupt nature of man that keeps him from recognizing as true God's testimony. Given that such a man will accept the testimony of other men as truth, it is indeed a sorry state of affairs that he'll not accept the judge's own testimony. Since God's testimony is in reality more sure than that of deceitful men, we can rest in certainty on our faith in Christ Jesus who alone has been put forth by God as the proper object of our faith. This faith hears internal testimony, not leaning on some external factor, and is therefor more firm.
- 5:10
- Since God must surely hold His own truth to be most valuable, it is extreme blasphemy to declare Him to have lied in proclaiming the Gospel. Goodness without the Gospel remains demonic, for it still rejects the claims of God; denying His truth, and thereby His essence.
- 5:11
- The exhortation to believe God's testimony is sweetened by showing His promise and purpose within that testimony - that we might live eternally with Him. This ought to suffice to bring us from believing to loving His truth. Life is God's gift to us, and until He gives it, we cannot possibly obtain it - there is no place for merit here. This life-gift cannot be found except we have it from the Gospel, for only there has God made clear the plan of His love for us; and it cannot be found except in Christ, for that is what the revealed plan reveals - that only in Christ may we find life.
- 5:12
- Indeed, life is only found in Christ. Those who have not found faith in Christ, are separated from life. This truth necessarily excludes those heroes of mankind who didn't know Christ. This is not unreasonable, as we see only the surface, where God sees the heart - and the heart that doesn't know Christ cannot be pure. (Lk 16:15 - what is esteemed by men is still detestable in God's eyes.) Furthermore, since righteousness for man can only exist in remission of sins, and remission of sins is solely found in Christ, it follows that all who remain without Christ remain under the sentence of death. The example of Cornelius cannot be taken to show things otherwise. (Ac 10:2 - as a God-fearer, he must have had some understanding of the Mediator.) In some, faith is an immediate thing - appearing as soon as Christ is introduced.