Bearing Fruits in Keeping with Repentance

This weeks passage is copied here below.
Luke 3:7-18 So he began saying to the crowds who were going out to be baptized by him, "You brood of vipers, who warned you to flee from the wrath to come?8) "Therefore bear fruits in keeping with repentance, and do not begin to say to yourselves, 'We have Abraham for our father,' for I say to you that from these stones God is able to raise up children to Abraham. (9) "Indeed the axe is already laid at the root of the trees; so every tree that does not bear good fruit is cut down and thrown into the fire." (10) And the crowds were questioning him, saying, "Then what shall we do?" (11) And he would answer and say to them, "The man who has two tunics is to share with him who has none; and he who has food is to do likewise." (12) And some tax collectors also came to be baptized, and they said to him, "Teacher, what shall we do?" (13) And he said to them, "Collect no more than what you have been ordered to." (14) Some soldiers were questioning him, saying, "And what about us, what shall we do?" And he said to them, "Do not take money from anyone by force, or accuse anyone falsely, and be content with your wages." (15) Now while the people were in a state of expectation and all were wondering in their hearts about John, as to whether he was the Christ, (16) John answered and said to them all, "As for me, I baptize you with water; but One is coming who is mightier than I, and I am not fit to untie the thong of His sandals; He will baptize you with the Holy Spirit and fire. (17) "His winnowing fork is in His hand to thoroughly clear His threshing floor, and to gather the wheat into His barn; but He will burn up the chaff with unquenchable fire." (18) So with many other exhortations he preached the gospel to the people.

Some of the questions and observations I have are listed here:
1. John seems to indicate that water baptism and confession alone are not sufficient evidence that someone has repented or is following God.

2. What is John's expectation? Does this differ from what we hear in Christian circles?

3. Verse 18 says that John preached the Gospel. What is the Gospel? Did he preach it in verse 16? Is there a connection to what John is saying with Romans 1:16-17 and Romans 12:2?

Please write out your own thought, questions, or examples.