Joh 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.
Here Jesus first appears, in person, in John's account, who omits all the details given by Matthew and Luke of his earlier life. He was now thirty years old, and came from Galilee to Jordan to be baptized of John. This interview was after the baptism (Joh 1:33), and probably after the Temptation.
Behold the Lamb of God. Innocent like the lamb, to be offered as a lamb, "led as a lamb to the slaughter" (Isa 53:7). The lamb was commonly used as a sin offering (Lev 4:32), and when John points to Jesus as the Lamb of God he can only mean that God had provided him as a sacrificial offering.
The sin of the world. Not of Jews only, but of Gentiles. John points to Jesus as the world's Savior. (References from the People’s New Testament)
Not of Israel only, for whom the typical victims were exclusively offered. Wherever there shall live a sinner throughout the wide world, sinking under that burden too heavy for him to bear, he shall find in this “Lamb of God,” a shoulder equal to the weight. The right note was struck at the first - balm, doubtless, to Christ’s own spirit; nor was ever after, or ever will be, a more glorious utterance.