KJV - Remember therefore how thou hast received and heard, and hold fast, and repent. If therefore thou shalt not watch, I will come on thee as a thief, and thou shalt not know what hour I will come upon thee.
ASV - Remember therefore how thou hast received and didst hear; and keep `it', and repent. If therefore thou shalt not watch, I will come as a thief, and thou shalt not know what hour I will come upon thee.
BBE - Keep in mind, then, the teaching which was given to you, and be ruled by it and have a change of heart. If then you do not keep watch, I will come like a thief, and you will have no knowledge of the hour when I will come on you.
WEB - Remember therefore how you have received and heard. Keep it, and repent. If therefore you won't watch, I will come as a thief, and you won't know what hour I will come upon you.
YLT - `Remember, then, how thou hast received, and heard, and be keeping, and reform: if, then, thou mayest not watch, I will come upon thee as a thief, and thou mayest not know what hour I will come upon thee.