JUDE 3
"Beloved, when I gave all diligence
to write unto you of the common salvation, it was needful for me to write
unto you, and exhort [you] that ye should earnestly contend for the faith
which was once delivered unto the saints."
Jude (actually Yahudah) was
referring to the faith delivered to them by the Messiah himself, encouraging
them not to let it be changed by anyone.