Which is Baptism.
No. It's not "born of water and born of spirit" but of water and spirit.
But all this is absurd and perverse, and condemned by the Church as heretical.
For, in the first place, why does Christ here make mention of water? Why did He not say briefly and simply to Nicodemus, who was ignorant of Christian doctrines (whom He here catechises and instructs like a child), except any one be born again of the Holy Ghost?
2. Because in a similar way S. Paul, alluding to this conversation, (Titus iii. 5), calls baptism the laver of regeneration. There in this spiritual birth we are born again of water, and are made sons of God, who before were children of the devil and wrath (Eph. ii. 3).
3. All the Fathers and orthodox interpreters explain the passage in the same way as the Council of Trent (Sess. 7, Can. 2). Nor are the words in S. Matthew, “He shall baptize you with the Holy Ghost and with fire,” any contradiction. For there real fire is to be understood, as here true water. For there the day of Pentecost was referred to, when the Holy Ghost came down upon the apostles in the likeness of tongues of fire.
Very appropriately, moreover, was water ordained by Christ in baptism for this spiritual regeneration. 1. Because water excellently represents inward regeneration. For out of water at the beginning of the world were the whole heavens and all other things born and produced. 2. Because moisture, such as is in water, is a chief agent in the production of offspring, as physicists teach. Again, because justification is a cleansing of the soul from the filth of sin it is well figured by water. As S. Chrysostom says upon this passage, “Like as it were in a tomb our heads are submerged beneath the water: our old man being buried is hidden beneath the water, and then the new man ariseth in its stead.” Lastly, the commonness and abundance of water makes it to be convenient matter for the necessity of this sacrament. For it is everywhere easily procurable.
You may ask why Christ says, except a man be born of water and the Holy Ghost, and did not rather say, of water and the form of baptism? For water is the matter of baptism, but the form is, I baptize thee in the Name of the Father and of the Son and of the Holy Ghost. For the sacrament of baptism consists of its matter and form, as its essential parts. I reply, because Christ wished to describe to Nicodemus, a prejudiced old man, the new teaching of spiritual life and generation, by means of the analogy and similitude of natural generation, in which a father and mother concur. So in like manner to spiritual regeneration, which takes place in baptism, water as it were the mother concurs, and the Holy Ghost as the Father. For He is the chief agent and producer of grace and holiness, by which the children of God are born again in baptism.
From this passage S. Augustine (lib. 1, de peccat. c. 10) proves, against Pelagius, that infants are born in original sin. For that is the reason why they must be born again in baptism, that they may be cleansed from that sin. And he exposes the folly of the Pelagians, who, in order to elude the force of this passage, said that infants dying without baptism would enter into the kingdom of heaven and eternal life, but not into the kingdom of God; as if the kingdom of God were something different from the kingdom of heaven.