The next day he saw Jesus coming towards him and declared, ‘Here is the Lamb of God who takes away the sin of the world! This is he of whom I said, “After me comes a man who ranks ahead of me because he was before me.” I myself did not know him; but I came baptizing with water for this reason, that he might be revealed to Israel.’ And John testified, ‘I saw the Spirit descending from heaven like a dove, and it remained on him. I myself did not know him, but the one who sent me to baptize with water said to me, “He on whom you see the Spirit descend and remain is the one who baptizes with the Holy Spirit.” And I myself have seen and have testified that this is the Son of God.’
The next day John again was standing with two of his disciples, and as he watched Jesus walk by, he exclaimed, ‘Look, here is the Lamb of God!’ The two disciples heard him say this, and they followed Jesus. When Jesus turned and saw them following, he said to them, ‘What are you looking for?’ They said to him, ‘Rabbi’ (which translated means Teacher), ‘where are you staying?’ He said to them, ‘Come and see.’ They came and saw where he was staying, and they remained with him that day. It was about four o’clock in the afternoon. One of the two who heard John speak and followed him was Andrew, Simon Peter’s brother. He first found his brother Simon and said to him, ‘We have found the Messiah’ (which is translated Anointed). He brought Simon to Jesus, who looked at him and said, ‘You are Simon son of John. You are to be called Cephas’ (which is translated Peter).Note that John's disciples did not answer Jesus. Their answer can be deduced from their description of Jesus to Peter, "We have found the Messiah", but they should have also mentioned John's description of Jesus as the sacrificial lamb, not exactly the kind of Messiah that Israel was expecting.
Matthew Henry (1706) in his concise commentaries had this to say,
"Verses 29-36 John saw Jesus coming to him, and pointed him out as the Lamb of God. The paschal lamb, in the shedding and sprinkling of its blood, the roasting and eating of its flesh, and all the other circumstances of the ordinance, represented the salvation of sinners by faith in Christ. And the lambs sacrificed every morning and evening, can only refer to Christ slain as a sacrifice to redeem us to God by his blood. John came as a preacher of repentance, yet he told his followers that they were to look for the pardon of their sins to Jesus only, and to his death... "
"Verses 37-42 The strongest and most prevailing argument with an awakened soul to follow Christ, is, that it is he only who takes away sin. Whatever communion there is between our souls and Christ, it is he who begins the discourse. He asked, What seek ye? The question Jesus put to them, we should all put to ourselves when we begin to follow Him, What do we design and desire? In following Christ, do we seek the favor of God and eternal life? He invites them to come without delay. Now is the ( 2 Corinthians. 6:2 ) is, wherever it be. We ought to labor for the spiritual welfare of those related to us, and seek to bring them to Him. Those who come to Christ, must come with a fixed resolution to be firm and constant to him, like a stone, solid and steadfast; and it is by his grace that they are so."What are you looking for? I suggest sitting down and making a list, and then thinking about how Jesus fulfills each of those desires, and if there are any wishes, wants, or dreams that do not seem to be answered by following Jesus, then you probably should cross them off your list.
CS Lewis in "Mere Christianity" put it this way,
"The Apostles themselves, who set on foot the conversion of the Roman Empire, the great men who built up the Middle Ages, the English Evangelicals who abolished the Slave Trade, all left their mark on Earth, precisely because their minds were occupied with Heaven. It is since Christians have largely ceased to think of the other world that they have become so ineffective in this. Aim at Heaven and you will get earth 'thrown in': aim at earth and you will get neither."What are you looking for?