And looking upon Jesus as He walked, he saith, Behold the Lamb of God! – John 1:36

John said in his preaching, “Behold the Lamb of God, which taketh away the sin of the world.” He pointed out Christ as the Sin-bearer, bearing human guilt in His own person. That is the master-key which lets men into the kingdom of heaven. Oh! how I do delight to preach Christ as the Substitute, Christ as the atoning sacrifice; and when you have heard Christ preached in that way, it makes you ready, “a people prepared for the Lord.” How can men come to Christ if they do not know what Christ has done for them? If you do not understand that He suffered in your stead, the Just for the unjust, to bring you to God, how can you come to Christ? But when you have learned that holy and blessed doctrine of Christ’s propitiation for human sin, why, then, methinks, you will leap at the very sound of it, and say, “Yes, I will take this propitiation to be a sacrifice for me. Blessed Lamb of God-

“‘My faith would lay her hand
On that dear head of Thine,
While like a penitent I stand
And there confess my sin.'”

My friend, you have come to the cross-roads; peradventure, if you reject the Saviour, it will be your last rejection of Him, and it will finally seal your doom; and I am sure, with no peradventure whatever, that if you look to Jesus, and trust to His finished work, you shall be saved, and saved for ever. ~ C.H. Spurgeon

https://www.blueletterbible.org/Comm/spurgeon_charles/sermons/2404.cfm