No New Revelation!
John Calvin
"For in [Christ] 'all treasures of knowledge and wisdom are hid' (Col. 2:3) with such great abundance and richness that either to hope for or to seek any new addition to these treasures is truly to arouse God's wrath and provoke him against us. It is for us to hunger for, seek, look to, learn, and study Christ alone, until that great day dawns when the Lord will fully manifest the glory of his Kingdom (cf. I Cor. 15:24) and will show himself for us to see him as he is (I John 3:2). And for this reason this age of ours is designated in the Scriptures as 'the last hour' (I John 2:18), the 'last days' (Heb. 1:2), the 'last times' (I Peter 1:20), that no one should delude himself with a vain expectation of some new doctrine or revelation. 'For at many times and in many ways the Heavenly Father formerly spoke through the prophets; but in these last days he has spoken in his beloved Son' (Heb. 1:1-2), who alone can reveal the Father (Luke 10:22); and he has indeed manifested the Father fully, as far as we require, while we now see him in a mirror (I Cor. 13:12)" (Institutes 4.18.20).
"This, however, remains certain: the perfect doctrine he has brought has made an end to all prophecies. All those, then, who, not content with the gospel, patch it with something extraneous to it, detract from Christ's authority. The Voice that thundered from heaven, 'This is my beloved Son; ... hear him' (Matt. 17:5; cf. Matt. 3:17), exalted him by a singular privilege beyond the rank of all others. Then this anointing was diffused from the Head to the members, as Joel had foretold: 'Your sons shall prophesy and your daughters ... shall see visions,' etc. (Joel 2:28). But when Paul says that He was given to us as our wisdom (I Cor. 1:30), and in another place, 'In him are hid all the treasures of knowledge and understanding' (Col. 2:3), he has a slightly different meaning. That is, outside Christ there is nothing worth knowing, and all who by faith perceive what he is like have grasped the whole immensity of heavenly benefits. For this reason, Paul writes in another passage: 'I decided to know nothing precious ... except Jesus Christ and him crucified' (I Cor. 2:2). This is very true, because it is not lawful to go beyond the simplicity of the gospel And the prophetic dignity in Christ leads us to know that in the sum of doctrine as he has given it to us all parts of perfect wisdom are contained" (Institutes 2.15.2).
"And when he speaks of the last times, he intimates that there is no longer any reason to expect any new revelation; for it was not a word in part that Christ brought, but the final conclusion. It is in this sense that the Apostles take ' the last times' and 'the last days.' And Paul means the same when he says, 'Upon whom the ends of the world are come' (I Cor. 10:11). If God then has spoken now for the last time, it is right to advance thus far; so also when you come to Christ, you ought not to go farther: and these two things it is very needful for us to know. For it was a great hindrance to the Jews that they did not consider that God had deferred a fuller revelation to another time; hence, being satisfied with their own Law, they did not hasten forward to the goal. But since Christ has appeared, an opposite evil began to prevail in the world; for men wished to advance beyond Christ. What else indeed is the whole system of Popery but the overleaping of the boundary which the Apostle has fixed? As, then, the Spirit of God in this passage invites all to come as far as Christ, so he forbids them to go beyond the last time which he mentions. In short, the limit of our wisdom is made here to be the Gospel" (Comm. on Heb. 1:1).