'Lamb's' in the Bible

I told him, "My lord, you know." He said to me, "These are those who came out of the great tribulation. They washed their robes, and made them white in the Lamb's blood.

They overcame him because of the Lamb's blood, and because of the word of their testimony. They didn't love their life, even to death.

And there came unto me one of the seven angels which had the seven vials full of the seven last plagues, and talked with me, saying, Come hither, I will shew thee the bride, the Lamb's wife.

The city wall had 12 foundations, and the 12 names of the Lamb’s 12 apostles were on the foundations.

And there shall in no wise enter into it any thing that defileth, neither whatsoever worketh abomination, or maketh a lie: but they which are written in the Lamb's book of life.