Easton's Bible Dictionary (1897)
The author was “Judas, the brother of James” the Less (Jude 1:1), called also Lebbaeus (Matt. 10:3) and Thaddaeus (Mark 3:18). The genuineness of this epistle was early questioned, and doubts regarding it were revived at the time of the Reformation; but the evidences in support of its claims are complete. It has all the marks of having proceeded from the writer whose name it bears. There is nothing very definite to determine the time and place at which it was written.
It was apparently written in the later period of the apostolic age, for when it was written there were persons still alive who had heard the apostles preach (ver. 17). D. 66 or 70, and apparently in Palestine. The epistle is addressed to Christians in general (ver. 1), and its design is to put them on their guard against the misleading efforts of a certain class of errorists to which they were exposed. ” The striking resemblance this epistle bears to 2 Peter suggests the idea that the author of the one had seen the epistle of the other.
The doxology with which the epistle concludes is regarded as the finest in the New Testament.
Smith's Bible Dictionary (1863)
Its author was probably Jude, one of the brethren of Jesus, the subject of the preceding article. D. 65. The object of the epistle is plainly enough announced ver. 3; the reason for this exhortation is given ver.