A distinction between the outward sign and an inward spiritual reality would clarify Jesus’ conversation with Nicodemus.
Jesus answered, "Truly, truly, I say to you, unless one is born of water and 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. "Do not be amazed that I said to you, ‘You must be born again.’ “The wind blows where it wishes and you hear the sound of it, but do not know where it comes from and where it is going; so is everyone who is born of the Spirit.” Nicodemus said to Him, “How can these things be?” Jesus answered and said to him, "Are you the teacher of Israel and do not understand these things?
(John 3:5-10 NASB)
Nicodemus indicates that he does not understand what Jesus is talking about. Jesus says that he should be able to understand it as a teacher of Israel. This would indicate that Jesus was not speaking of some new teaching but something that Nicodemus should have already been aware of as a Pharisee. Water baptism is not something taught in the Old Testament and Nicodemus would not have been expected to know of it as a Jewish teacher. He would, however, be expected to understand the inward circumcision of the heart that had been referred to in the Old Testament. If Jesus was speaking of there being a new birth through water baptism, why would He have spoken about the Spirit in reference to the wind and not knowing where it comes from and where it was going? If the actual rebirth took place with the water baptism it would be absolutely possible to know where the Spirit was acting since it would act on the person being baptised in water. However, if the rebirth is separate from the actual sacrament of water baptism, it would be true to say we would not know who the Spirit would regenerate.
Jesus’ language in John 3, appears to refer specifically to Ezekiel 36 where God says He will sprinkle us with clean water and give a new heart and spirit. It should be remembered that the working of the Holy Spirit is often compared to water.
"Then I will sprinkle clean water on you, and you will be clean; I will cleanse you from all your filthiness and from all your idols. "Moreover, I will give you a new heart and put a new spirit within you; and I will remove the heart of stone from your flesh and give you a heart of flesh. "I will put My Spirit within you and cause you to walk in My statutes, and you will be careful to observe My ordinances.
(Ezekiel 36:25-27 NASB)
Removing our heart of stone would equate with the spiritual circumcision of the heart. It would also link with the new covenant promised in Jeremiah 31, where God promises to write the law on our hearts.
“Behold, days are coming,” declares the LORD, “when I will make a new covenant with the house of Israel and with the house of Judah, not like the covenant which I made with their fathers in the day I took them by the hand to bring them out of the land of Egypt, My covenant which they broke, although I was a husband to them,” declares the LORD. “But this is the covenant which I will make with the house of Israel after those days,” declares the LORD, "I will put My law within them and on their heart I will write it; and I will be their God, and they shall be My people. “They will not teach again, each man his neighbor and each man his brother, saying, ‘Know the LORD,’ for they will all know Me, from the least of them to the greatest of them,” declares the LORD, “for I will forgive their iniquity, and their sin I will remember no more.”
(Jeremiah 31:31-34 NASB)
It would also fit with David’s prayer in Psalm 51 where he asks God to blot out his sins, give him a clean heart and renew his spirit.
Hide Your face from my sins And blot out all my iniquities. Create in me a clean heart, O God, And renew a steadfast spirit within me.
(Psalms 51:9-10 NASB)
The recognition of a distinction between outward water baptism and inward spiritual baptism corresponding to the same distinction between circumcision of the flesh and circumcision of the heart, would allow for the reality that people under the Old Testament were saved in the same way that we are under the New Testament. Each of us experiences an inner rebirth through the Spirit even though different sacramental signs are used. Some, such as Cornelius and his household, are saved by receiving the Holy Spirit before the sacrament of baptism, just as Abraham was before he was circumcised, and some after the sacrament, just as Scripture says that those who had already had there flesh circumcised would later have their hearts circumcised. It would seem clear that the physical act of circumcision is not the relevant point of consideration under the Old Testament. If it was then now women would have been saved under the Old Testament and neither would Gentiles since neither group would have received physical circumcision.
It appears to some extent that the Catholic Church recognizes, at least implicitly, that someone can receive spiritual baptism without water baptism. It would justify the recognition of both the Baptism of Blood and the Baptism of Desire where someone is recognized as having received the benefit of baptism even without the sacrament. They have already received the spiritual baptism upon believing. It would also deal with the case of adults who are baptised without actually believing. If an unbelieving adult is baptised it is recognized that the sacrament they received cannot save them since they don’t believe. However, since they have already received the outward sign, if they do become believers they do not receive the sacrament again. In such a case can it really be argued that it is the water baptism that has saved them? On belief they receive the true spiritual baptism. Placing the emphasis on spiritual baptism through belief would also explain why Paul told the Corinthians that he was not sent to baptise since the important thing was preaching so they could believe.
If the Sacrament of Baptism is not required, does that mean we should not receive it? Of course not since Jesus and Scripture tells us to receive the sacrament. If we are unwilling to do so then have we truly believed? Please note also, that as a Prebyterian I accept infant baptism as it claims the covenant promises for our children.