"The Kingdom of Heaven is at hand", is not a place but a person. Jesus was saying the He is here and to receive the Kingdom, you must receive Him. God really does not care what we think about our sin, what he is going to judge us for is what we do with Christ.
Both Peter and Paul are making it clear that the Gospel is Christ in you the Hope of Glory.
Act 15:7 And when there had been much disputing, Peter rose up, and said unto them, Men [and] brethren, ye know how that a good while ago God made choice among us, that the Gentiles by my mouth should hear the word of the gospel, and believe.
Rom 2:16 In the day when God shall judge the secrets of men by Jesus Christ according to my gospel.
What was John telling them to repent of? Their repentance was outside of themselve in into Christ. What was their baptism in water for, it did nothing to them but get them wet. Because Israel was and would not accept their salvation by the free gift of Christ, which He was offering to them by the Grace of God through faith, which the Faith of Jesus Christ had not come yet, and they would not believe, even when John telling them that He is coming and He will baptize them with the Holy Spirit, not water.
Act 14:27 And when they were come, and had gathered the church together, they rehearsed all that God had done with them, and how he had opened the door of faith unto the Gentiles.
¶ Beloved, when I gave all diligence to write unto you of the common salvation, it was needful for me to write unto you, and exhort [you] that ye should earnestly contend for the faith which was once delivered unto the saints.
Gal 3:14 That the blessing of Abraham might come on the Gentiles through Jesus Christ; that we might receive the promise of the Spirit through faith.
Not the faith of Abraham but the blessings of Abraham promised by God, that is the Seed, Jesus Christ.
Galatians 3:24-26 Wherefore the law was our schoolmaster to bring us unto Christ, that we might be justified by faith. But after that faith is come, we are no longer under a schoolmaster. For ye are all the children of God by faith in Christ Jesus. The word in Christ means: Strong's Greek Dictionary
1722. en
a relation of rest (intermediate between 1519 and 1537); "in," at, (up-)on, by, etc.:--about, after, against, + almost, X altogether, among, X as, at, before, between, (here-)by (+ all means), for (... sake of), + give self wholly to, (here-)in(-to, -wardly), X mightily, (because) of, Gal 3:25 But after that faith is come, we are no longer under a schoolmaster. (The Law)
They were not being baptized into Christ's death, they were only being cleansed in the flesh as a show of why they should accept the free gift Christ was offering them, that is Himself. That is why John baptized in water with repentance so they could accept what Jesus was, Their King and Savior, they would not.
After the Cross salvation comes by believing the Jesus Christ is the Son of God and Christ is birthed in the believer and the believer is baptized into Christ's death. Then when Christ's prayer answered by the Father and puts the Holy Spirit into the believer, the believer can then turn around by the Word of God Himself which is in Him and the Holy Spirit leading the believer to repentance because the believer now knows what to repent of by the Holy Spirit teaching us to the Mind of Christ which we now have.
Repentance before salvation is the works of man.
Repentance after salvation is the Works of the Holy Spriit to the Mind of Christ we have now been give at our new birth.
1Cr 2:16 For who hath known the mind of the Lord, that he may instruct him? But we have the mind of Christ.
Rom 7:25 I thank God through Jesus Christ our Lord. So then with the mind I myself serve the law of God; but with the flesh the law of sin.
Rom 15:6 That ye may with one mind [and] one mouth glorify God, even the Father of our Lord Jesus Christ.
Repent and be baptized cannot be the means of salvation. John 3:15-17 That whosoever believeth in Him should not perish, but have eternal life. For God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life. For God sent not his Son into the world to condemn the world; but that the world through him might be saved.
Mar 16:16 He that believeth and is baptized shall be saved; but he that believeth not shall be damned.
Notice that believing is first and then baptized into Christ and the Holy Spirit. No water baptism here. Water baptism is a sign for all that believe and even to unbelievers that Jesus Christ is now our Life and as a show of obedience and Love, not a Law, that we are not Christ persons'. Christians, Christ-ones. Christ Life.
Just a few scriptures to make it clear.
Jhn 17:3 And this is life eternal, that they might know thee the only true God, and Jesus Christ, whom thou hast sent.
Jhn 20:31 But these are written, that ye might believe that Jesus is the Christ, the Son of God; and that believing ye might have life through his name.
Rom 5:17 For if by one man's offence death reigned by one; much more they which receive abundance of grace and of the gift of righteousness shall reign in life by one, Jesus Christ.)
Rom 5:21 That as sin hath reigned unto death, even so might grace reign through righteousness unto eternal life by Jesus Christ our Lord.
Rom 6:4 Therefore we are buried with him by baptism into death: that like as Christ was raised up from the dead by the glory of the Father, even so we also should walk in newness of life.
Rom 6:23 For the wages of sin [is] death; but the gift of God [is] eternal life through Jesus Christ our Lord.
Rom 8:2 For the law of the Spirit of life in Christ Jesus hath made me free from the law of sin and death.
Rom 8:10 And if Christ [be] in you, the body [is] dead because of sin; but the Spirit [is] life because of righteousness
Where is our life, repentance, and baptise?
It is in Christ, not ourselves. God does not need to be told how bad we were and are, He knows.
Believe and thou shalt be saved and then work our your salvation with fear and trembling. For it is a terrible things to fall into the hands of a living God. Before we believed and are saved we were not even in His Hands. We were all going to hell and He had nothing to do with us. He has only worked with One man for us to fall into the Hands of a living God, That is Jesus Christ and you must believe that Jesus Christ is the Son of the Living God, which is revealed from above by God the Father.
Man cannot do this by any works. Matthew 16:16-19 And Simon Peter answered and said, Thou art the Christ, the Son of the living God. And Jesus answered and said unto him, Blessed art thou, Simon Barjona: for flesh and blood hath not revealed it unto thee, but my Father which is in heaven. And I say also unto thee, That thou art Peter, and upon this rock I will build my church; and the gates of hell shall not prevail against it. And I will give unto thee the keys of the kingdom of heaven: and whatsoever thou shalt bind on earth shall be bound in heaven: and whatsoever thou shalt loose on earth shall be loosed in heaven.
Who is the Rock, it is certainly not Peter, it is Jesus Christ the Son of God and reveled by the Father, this is what Christ will build His Church upon, that is the Body of Christ His Church.
In Christ: Phillip