Irenaeus specifically addresses what Jesus says in John ch. 3 here:
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It was not for nothing that Naaman of old, when suffering from leprosy, was purified upon his being baptized, but [it served] as an indication to us. For as we are lepers in sin, we are made clean, by means of the sacred water and the invocation of the Lord, from our old transgressions; being spiritually regenerated as new-born babes, even as the Lord has declared: 'Except a man be born again through water and the Spirit, he shall not enter the kingdom of heaven.'" - Irenaeus, Fragment 34 of the Lost Fragmented Works of Irenaeus
Clement of Alexandria says the following, referencing Jesus' words in John 6, speaking of how we are nourished by His flesh and blood.
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The Word is all to the child, both father and mother and tutor and nurse. 'Eat ye My flesh,' He says, 'and drink My blood.' Such is the suitable food which the Lord ministers, and He offers His flesh and pours forth His blood, and nothing is wanting for the children's growth. O amazing mystery! We are enjoined to cast off the old and carnal corruption, as also the old nutriment, receiving in exchange another regimen, that of Christ, receiving Him if we can, to hide Him within; and that, enshrining the Savior in our souls, we may correct the affections of our flesh." - Clement of Alexandria, The Instructor, Book I. Ch. 6
What exactly are you looking for? What would satisfy your question?
Because consistently the fathers talk about Baptism and the Lord's Supper; that Baptism is new birth, that the Eucharist is the very flesh and blood of Jesus.
Looking for direct scriptual references in the earliest fathers is difficult, because they wrote at a time after most of the books of the New Testament were written, but before there was a New Testament. Works were already in circulation, and the earliest "New Testament" probably looked mostly like a collection of Paul's letters, and maybe at least some of the Gospels (it's really impossible to say at this point in history).
The earliest mention of all four Gospels (and only those four Gospels) as Scripture is Irenaeus, though he treats it as a matter of fact, which indicates that the acceptance of only these four Gospels had been around already for a time and was common among the churches. And we see the earliest list of New Testament books in the Muratorian Fragment, which lists all four Gospels.
As such, we don't really start to see specific Gospel text references until the late 2nd and into the early 3rd century.
That isn't to say that references and quotes don't exist (they do), but it's uncommon.
The Church seems to have become highly motivated to canonize Scripture as a response to prominent 2nd century heretics, namely Marcion of Sinope and Montanus of Phrygia.
Marcion was the son of a wealth merchant family from Sinope, on the coast of the Black Sea. Without getting too bogged down in details, Marcion while visiting the Church in Rome came to the conclusion that that the God Jesus talked about was an entirely different God than the God mentioned in the Jewish Scriptures. Marcion taught that Jesus introduced a new god, "Abba", and that the old god, YHWH worshiped by the Jews was in fact a false god. Unsurprisingly, this got Marcion in trouble with the local clergy in Rome. He ended up being excommunicated for heresy, but instead of repenting he went on to create his own rival Marcionite Church. To that end, Marcion decided to create the first ever "Christian" Bible, consisting only of the Gospel of Luke (which Marcion edited and renamed "The Gospel of the Lord"), and most of the Epistles of Paul (again, edited to remove anything Jewish).
Marcion's movement was a big deal. And copies of Marcion's edited works of Paul's letters actually caused some trouble in the early Church, as both the authentic and the now manipulated letters of Paul existed at the same time. Marcion's "Bible" is often credited as being one of the impetuses for the Church to start having clearer boundaries over what is and isn't Scripture.
The second issue was the Montanist movement. In Phrygia a man by the name of Montanus along with two women began preaching that the new era of the Spirit had come, and that Montanus and his two prophetesses were the prophets and harbingers of this new era. Montanus' teaching (Montanism) was that history was to be divided into three epochs, the age of the Father, the age of the Son, and the age of the Spirit. According to Montanus, the age of the Father was the time before Christ, the age of the Son was the time of Christ until the time of Montanus, and now with Montanus the new era of the Spirit has come. Claiming to bear new revelations, and preaching a highly ascetical and moralistic rigor, Montanism became quite attractive, it even fooled Tertullian of Carthage, a formerly highly respected Christian theologian and considered the first of the Latin Fathers (that is, the earliest Christian writer who wrote in Latin, as opposed to Greek).
So between these two: Marcionitism which sought to produce a peculiarly Marcionite Bible; and the Montanists on the other who essentially claimed that Montanus and his companions were the literal mouthpiece of the Holy Spirit; the Church's response was to emphasize the received revelation and received Scriptures--and it is at this point that we start to see local Christian bishops and communities start to codify a Canon of Scripture (though there was already an emerging proto-New Testament at the time anyway).
So when dealing with this early history, it is important to temper our expectations. Instead we have to rely on the information we do have.
And you are free to see it for yourself. Here's a website where you can search any Bible reference you want and get a list of results from the writings of the fathers:
Church Fathers Scripture Index and you can browse the fathers at here:
CHURCH FATHERS: Home
-CryptoLutheran