Judas 1:20

Building up yourselves - Having the most holy faith - the Gospel of our Lord Jesus, and the writings of his apostles, for your foundation; founding all your expectations on these, and seeking from the Christ who is their sum and substance; all the grace and glory ye need. Praying in the Holy Ghost - Holding fast the Divine influence which ye have received, and under that influence making prayer and supplication to God. The prayer that is not sent up through the influence of the Holy Ghost is never likely to reach heaven.

Resuming Jde 1:17. building up yourselves--the opposite to the "separate themselves" (Jde 1:19): as "in the Holy Ghost" is opposed to "having not the Spirit." on--as on a foundation. Building on THE FAITH is equivalent to building on Christ, the object of faith. praying in the Holy Ghost-- (Rom 8:26; Eph 6:18). The Holy Spirit teaches what we are to pray for, and how. None can pray aright save by being in the Spirit, that is, in the element of His influence. CHRYSOSTOM states that, among the charisms bestowed at the beginning of the New Testament dispensation, was the gift of prayer, bestowed on someone who prayed in the name of the rest, and taught others to pray. Moreover, their prayers so conceived and often used, were received and preserved among Christians, and out of them forms of prayer were framed. Such is the origin of liturgies [HAMMOND].

But ye, beloved,.... See Gill on , building up yourselves on your most holy faith; some copies, and the Complutensian edition, read, "our most holy faith"; meaning the doctrine of faith in all its branches, which is holy, a most holy doctrine; which displays the holiness of God, and is a means of beginning and increasing internal holiness in the saints, and of encouraging and exciting them to external holiness of life and conversation: this phrase, , "holy faith", is in use with the Jews (k): and it becomes the saints to build up one another upon this; the doctrine of faith, is a foundation to build upon, particularly what regards the person, offices, and grace of Christ, and is itself of an edifying nature; and they should not content themselves with their present knowledge of it, but seek for an improvement in it; and though they were passive when first built on Christ and his doctrines, and though ministers are greatly instruments in building of them up more and more; yet they are capable of building up themselves, and one another, by attending on the ministry of the word, and by private conversation, with each other, and particularly by praying in the Holy Ghost; which is a special means of increase and establishment in the doctrine of faith; the Holy Ghost is the author and enditer of prayer, and an assister in it; without him saints cannot call God their Father, nor pray with faith and fervency, or with freedom and liberty, (k) Zohar in Gen. fol. 47. 4.

We have here, I. An account of the penman of this epistle, a character of the church, the blessings and privileges of that happy society (Jde 1:1, Jde 1:2). II. The occasion of writing this epistle (Jde 1:3). III. A character of evil and perverse men, who had already sprung up in that infant state of the church, and would be succeeded by others of the like evil spirit and temper in after-times (Jde 1:4). IV. A caution against hearkening to and following after such, from the severity of God towards the unbelieving murmuring Israelites at their coming out of Egypt, the angels that fell, the sin and punishment of Sodom and Gomorrah (Jde 1:5-7). V. To these the apostle likens the seducers against whom he was warning them, and describes them at large, (Jde 1:8-10, inclusive). VI. Then (as specially suitable to his argument) he cites an ancient prophecy of Enoch foretelling and describing the future judgment (Jde 1:14, Jde 1:15). VII. He enlarges on the seducers' character, and guards against the offence which honest minds might be apt to take at the so early permission of such things, by showing that it was foretold long before that so it must be (Jde 1:16-19). VIII. Exhorts them to perseverance in the faith, fervency in prayer, watchfulness against falling from the love of God, and a lively hope of eternal life (Jde 1:20, Jde 1:21). IX. Directs them how to act towards the erroneous and scandalous (Jde 1:22, Jde 1:23). And, X. Closes with an admirable doxology in the last two verses.

1:20 your most holy faith: As in 1:3, faith refers to what Christians believe, the doctrinal and ethical core of Christian identity, which false teachers threaten. Believers must therefore devote themselves to it.