Jesus said you will only enter the Heavenly Kingdom if you are born of: (John 3:5)
2) Spirit (Holy Ghost)
The water is a symbol of cleansing and therefore for a Christian it happens when we are baptized by water into Christ and are justified by the Grace of God.
What does to be justified mean:
Justification (Gift of God)
In Christian theology, is God's act of removing the guilt and penalty of sin while at the same time declaring a sinner righteous through Christ's atoning sacrifice. The righteousness of Christ is credited/imputed/counted to the sinner's account through FAITH ALONE in Christ alone.
This is the part where we are CALLED by MAN to CHRIST through the preaching of the gospel. (The Great Commission started by the disciples and apostles of Christ)
The second part of salvation is the purging by FIRE of the old carnal minded man of flesh to a spiritually minded saint who is moulded into the personage of Jesus according to all his beatitudes, thereby coming into the fullness of Christ by FAITH and WORKS.
This is the second baptism the baptism of fire and Holy Ghost that becomes a life-long process called sanctification (to make Holy and complete in the fullness of Christ according to his beatitudes).
Many are called by man (justified by water baptism and awarded the gift of grace) but few are chosen by God the Holy Spirit who sanctifies them and places the seal of the living God on them, so that they can migrate to the new Heavenly country New Jerusalem.
Zechariah 13:9 (NIV)
This third I will bring into the FIRE; I will refine them like silver and test them like gold. They will call on my name and I will answer them; I will say, 'They are my people,' and they will say, 'The LORD is our God.'"
So there are two baptisms involved in a christian narrow walk by faith in God towards salvation, one is instant and is awarded according to the grace of god as a gift and is called justification, the other one that functions as a SEALING of the baptized (by water)i n Christ, is the life long baptism of fire and sanctification of the already justified.
One is conditional upon the other and sanctification cannot proceed until one is justified or cleared as being transgressors of the law.
So this is how one can understand how we are saved for as it is declared we must be sanctified to enter into the Kingdom of Heaven for water alone will not get you there.
So both water and fire must be satisfied according to the will of God the Holy Spirit before he grants you the Heavenly visa.
Having said all that we can use scripture and an analogy to further enlighten this concept.
Before Christ we were condemned to death and awaiting our day of execution on death row because we fell under the curse of the Mosaic Law.
Christ having gained us victory through his death on the cross prevailed over death, the devil who had power over death and most importantly the apparatus of death that is SIN.
Once we are justified by the blood of the Lamb of God we then become cleared from being law breakers and therefore are pardoned from the letter of the law. This is not a get out of jail and death row pass but what the water baptism does is impute Christ's righteousness on us so that God now views us as if we have not broken any of his laws and statutes. God being the magistrate and judge now sees it fit since we are released on good behavior bond that was paid in full at cavalry we now walk as free men but must adhere to the parol conditions of the magistrate who is God the Holy Spirit. That is why God the Holy Spirit came down and His role was to be with us from our water baptism right through to when he will resurrect us on our third day (Hosea 6:2).
Sadly what most professing Christians do is accept the gift, mercy and grace of God being called by man in water baptism into Christ only to see superficial freedom and then do the BOLT and run in their own worldly path and desires forgetting about who they must communion (tabernacle) with (God the Holy Spirit), who is their parol and rehabilitation officer who will arbitrate and execute the life long baptism of fire in a pardoned prisoner of Christ (as Saint Paul declares).
So justification attaining to being baptized by water will only award you grace until you die then if you were not reformed as a pardoned prisoner of Christ, then you will NOT enter into the Kingdom of Christ in Heaven no matter what you think or others tell you.
You must have an experiential relationship with God as your ONLY Father and talk to him in your prayers, fasting and supplication and in so doing you are tabernackling with your God and observing the Holy Sabbath every minute of your narrow walk by faith with God (Lord of the Sabbath) in your life long sanctification (baptism of fire) / rehabilitation program set aside for you by God to change you from a carnally minded and hearted person to a spiritual born again faithful in the personage of Christ.
There are different degrees of sanctification for the baptized in Christ according to how God apportions them. The award or status in the Heavenly Country that Christ will grant you, will be to the degree that you fully submitted yourself and allowed His Holy Spirit to manifest His Good Works in you.
Therefore as apostle James 2:17 states correctly, faith without God's Works is dead faith and no faith at all since if one does fully submitt to God He will do no wrong for the works of God the Holy Spirit will manifest in him.
The kingdom of heaven is like unto a certain king (God Almighty), which made a marriage for his son (Jesus Christ), And sent forth his servants (Old Testament Prophets) to call them (Jews First) that were bidden to the wedding: and they would not come (Jews rejected the Son). Again, he sent forth other servants (Disciples and Apostles), saying, Tell them which are bidden, Behold, I have prepared my dinner: my oxen and my fatlings are killed, and all things are ready: come unto the marriage (Heavenly Kingdom). But they made light of it, and went their ways, one to his farm, another to his merchandise: And the remnant (Jewish Levitical Priesthood) took his servants (Disciples and Apostles), and entreated them spitefully, and slew (Jews killed His disciples and apostles) them. But when the king heard thereof, he was wroth: and he sent forth his armies (Roman Empire), and destroyed those murderers (Jewish Levitical Priesthood), and burned up their city (earthly Jerusalem 70AD). Then saith he to his servants (martyred saints), The wedding is ready (gates of Heavenly Kingdom New Jerusalem opened), but they which were bidden were not worthy (God rejected the Pharisaical Levitical Priesthood). Go ye therefore into the highways (Now start preaching to the Gentiles), and as many as ye shall find (Call them by Water Baptism), bid to the marriage. So those servants went out into the highways (to the Gentiles), and gathered together all as many as they found, both bad and good (even the bad God makes Holy, you will be surprised who is invited): and the wedding was furnished with guests. And when the king came in to see the guests, he saw there a man (Christian called to Christ by water baptism), by which had not on a wedding garment (Not Sanctified or Sealed by God the Holy Spirit): And he saith unto him, Friend, how camest thou in hither not having a wedding garment (Sanctification garment of the saints)? And he was speechless (the Christian thought he was in the Heavenly Kingdom because of the free gift he received without having to do anything but only believe and be baptized by water). Then said the king to the servants, Bind him hand and foot, and take him away, and cast him into outer darkness; there shall be weeping and gnashing of teeth.
For many are called, but few are chosen.
Many are called by man to Christ by the Water Baptism and are therefore justified in the sight of The Lord.
Sadly few are chosen or sanctified/sealed by God because they did not submit to the will of God the Holy Spirit who sanctifies them and thereby doing the runner whilst they were on parol and ignored the rehabilitation officer God the Holy Spirit.
The Christian in the above versus was shocked because he hedged his bet on being justified without lifting a finger and became complacent and attuned to the worldly way of life and felt that He did not need to be rehabilitated as a pardoned prisoner of Christ by His parol and rehabilitation officer.
The Lord's Word were in
Jesus answered, Verily, verily, I say unto thee, Except a man be born of water and of the Spirit, he cannot enter into the kingdom of God. That which is born of the flesh is flesh; and that which is born of the Spirit is spirit.
You must be born again of the Spirit of God who will quicken your mortal bodies on your day of resurrection (Romans 8:11).
Matthew 3:11 (NIV)
"I baptize you with water for repentance. But after me will come one who is more powerful than I, whose sandals I am not fit to carry. He will baptize you with the Holy Spirit and with FIRE (symbol for purging of old carnal self to a born again new creation in Christ).
You must be Born Again!