The twenty-first and last of the Epistles, and the penultimate book in the Bible, is Jude. It was written in Jerusalem in approximately 69 AD by the author after whom it is named. Although not one of the 12 disciples of Jesus, Jude did know him, and he is even said by some to have been Jesus' brother; though this relationship has been disputed.
Because Jude witnessed Jesus' resurrection, he is a firm believer in Christ, and wants to share the good news of salvation. However, this letter, like so many more of the Epistles, is concerned mostly with false teachers who are spreading errant doctrines amongst the Christian community.
"Jude, the servant of Jesus Christ, and brother of James, to them that are sanctified by God the Father, and preserved in Jesus Christ, and called: mercy unto you, and peace, and love, be multiplied."
Some Christians believe that both James and Jude were Jesus' brothers, referencing Matthew 13:55-56
"Is not this the carpenter’s son? is not his mother called Mary? and his brethren, James, and Joses, and Simon, and Judas?"
Whilst others believe that the term "brother" could mean "cousin" or even "friend"