Only found twice in the whole Bible!
John 1:29 The next day John seeth Jesus coming unto him, and saith, Behold the Lamb of God, which taketh away the sin of the world.
John 1:36 And looking upon Jesus as he walked, he saith, Behold the Lamb of God!
1 Peter 1:19 But with the precious blood of Christ, as of a lamb without blemish and without spot:
Lamb appears 25 times in the Book of Revelation most of the references are to a person. And study of these verses point to the Lamb being the Lord Jesus. (exception Revelation 13:8,11)
Revelation 5:8 And when he had taken the book, the four beasts and four and twenty elders fell down before the Lamb, having every one of them harps, and golden vials full of odours, which are the prayers of saints.
Revelation 5:13 And every creature which is in heaven, and on the earth, and under the earth, and such as are in the sea, and all that are in them, heard I saying, Blessing, and honour, and glory, and power, be unto him that sitteth upon the throne, and unto the Lamb for ever and ever.
Revelation 7:9 After this I beheld, and, lo, a great multitude, which no man could number, of all nations, and kindreds, and people, and tongues, stood before the throne, and before the Lamb, clothed with white robes, and palms in their hands;
Revelation 12:11 And they overcame him by the blood of the Lamb, and by the word of their testimony; and they loved not their lives unto the death.
Revelation 14:1 And I looked, and, lo, a Lamb stood on the mount Sion, and with him an hundred forty and four thousand, having his Father’s name written in their foreheads.
Revelation 21:14 And the wall of the city had twelve foundations, and in them the names of the twelve apostles of the Lamb.
Lamb appears 69 times in the Old Testament and mostly refers to a young sheep. One exception is in Isaiah prophesizing of the Lord’s crucifixion:
Isaiah 53:7 He was oppressed, and he was afflicted, yet he opened not his mouth: he is brought as a lamb to the slaughter, and as a sheep before her shearers is dumb, so he openeth not his mouth.
Conclusion
You need the Lamb’s blood applied, not to your doorpost as in the Passover (Exodus 12:7), but over your life (John 3:16-17). If you have not believed in the death, burial and resurrection (1 Corinthians 15:1-4) and confessed that Jesus is God (Romans 10:9) realizing your need for a Savior and trusted in Christ for eternal life, you are going to be led to the slaughter someday (Revelation 20:11-15). Only the blood of the Lamb of God can take away your sins. I suggest you trust in Christ and have His blood atone for your sins…or you will have to pay for your own sins someday and unfortunately, that will take all of eternity to pay.