Why were Some 1st-3rd Century Gentiles Drawn to Torah Whilst Others were Repulsed by it?

During the mid-first-century, there was no Christianity, only a Messianic sect of Judaism:

 "...there was no single "Gentile Christianity" in the mid-first century and scholars should discontinue its use so that they do not perpetuate this misunderstanding. The Christ-movement at this stage was a variant form of Judaism, existing within the synagogue community and Jewish sacred space, with local differentiations recognized." pg. 8 of "Gentile Christianity" and the Study of Christian Origins:  A Response to Terence L. Donaldson Focusing on Gentile Self-Identification

By the end of the first-century, Gentiles separated themselves from Messianic Judaism:

"The first Christians constituted a small group within Judaism.  Jesus had devoted his own ministry to Jews (Matt. 15:24), and his followers were Jews.  At an early date the apostles began to admit Gentiles to the movement, but the Christians remained a basically Jewish group for a few decades.  The new movement separated itself from its parent in the course of the first one hundred or so years of its existence.  There is no one point that marks the 'divorce,' and so we must be vague about dates, but by the end of the first century many (probably most) Christian groups considered themselves not to be Jewish.  By the end of the second century relatively few Christians would have identified themselves as Jews.  Christianity became a predominantly Gentile religion." [Sanders in an essay entitled "Reflections on Anti-Judaism in the New Testament and in Christianity"]

During the Patristic period of Christianity, the leaders of the Gentile Separatist movement (Christianity) formulated an anti-Jewish theology:

"By the end of the third century, the primary motifs of the Adversos Judaeos tradition, or theological anti-Jewishness, were firmly implanted in church Christology.  They laid the foundation for the Christian view of Jews and Judaism for centuries to come.  Indeed, it was the church leadership in the patristic period that actually formulated such a theology of contempt," (Rabbi Yechiel Eckstein).

But how did anti-Judaism first arise???

Perhaps you know better than me.  But here's a few suggestions:

(1) Pride (Romans 11); 

(2) Misinterpretation of the significance of the destruction of the Temple in 70 C.E.; 

(3) Misinterpretation of Yeshua's statements in the Gospels (e.g. "You are from your father the devil!"; 

(4) Misinterpretation of Acts 15; 

(5) Misinterpretation of Paul's seemingly anti-Jewish statements (e.g. 1 Thess. 2:14-16 "For you, brothers, became imitators of the churches of God in Christ Jesus that are in Judea, for you suffered the same things from your own compatriots as they did from the Jews, who killed both the Lord Jesus and the prophets, and drove us out; they displease God and oppose everyone by hindering us from speaking to the Gentiles so that they may be saved.  Thus they have constantly been filling up the measure of their sins; but God's wrath has overtaken them at last."); 

(6) Misinterpretation of Paul's seemingly antinomian statements (e.g. Romans 10:4 "Christ is the end of the law so that there may be righteousness for everyone who believes."); 

(7) Misinterpretation of Paul's seemingly supersessionist statements (e.g Romans 9:6-7  "It is not as though the word of God had failed.  For not all Israelites truly belong to Israel, and not all of Abraham's children are his true descendants."); 

(8) Sociology of group identification.  The Christians needed to demonize the Jews (the supposed "bad group") in order to prove that they (the Christians) belonged to the good group.  Also, anti-Jewish rhetoric served the purpose of differentiating the Christian group from the Jewish group and thus strengthened Christian identity; 

(9) Theological resentment.  The Christians needed to prove to themselves that G-d preferred them above the natural members of Israel (i.e. Jews); 

(10)  Message Differentiation.  To show the superiority of the Christian religion (over Judaism), the Christians needed anti-Jewish rhetoric to show that Judaism was inferior.  

You, dear reader, will probably think of other motivations for early anti-Jewish sentiment.  If so, let me know.  But let's keep going…

Up Until 386 C.E., there Persisted a Group of Uncircumcised Gentiles Who Believed in Yeshua AND Desired to Practice Judaism:

See earlier post HERE.

So now let's ask the finale question:

Why were some Gentiles in the 1st-3rd Centuries drawn to Torah?

The simplest answer I can suggest is that they saw G-d's love manifested in the Torah and then they felt the natural urge to reciprocate.  

But there were other reasons as well…

For example, in the Roman Empire in the first three centuries, a gentile who refused to honor the local gods was considered to be a traitor to his people:

"A useful way to contrast ancient and modern conceptualizations of 'religion' is to consider, in antiquity, the embeddedness of divinity.  Ancient gods were local in a dual sense.  First, they attached to particular places...Second, gods also attached to particular peoples: 'religion' ran in the blood.  Put differently:  cult was a type of ethnic designation, something that identified one's people or kinship group, the genos....More commonly, deities were identified through reference to the peoples who worshipped them:  the god of Israel, the gods of Rome, the god at Delos, and so on (cf. Acts 19:28: 'Great is Artemis of the Ephesians!')." pg. 3 of Christians in the Roman Empire in the First Three Centuries CE by Paula Fredriksen

Gentiles deemed traitors to the ancestral gods were subjected to all sorts of abuse:

"We know that those gentile Christians who refused to worship their ancestral gods became the target of pagan anxieties and, eventually, of pagan persecutions." pg. 7 Christians in the Roman Empire in the First Three Centuries CE by Paula Fredriksen

Thus, Gentiles in the Roman Empire had two choices:  (1) be a pagan or (2) associate with the synagogue.

The sociological pressure from the host culture seems like it would've driven the Gentile Believers into synagogues.  Once there it seems that the process of normalization would've taken over and Gentiles, immersed in Judaism, would've naturally assimilated into Jewish culture.  

Yes, it's a guess on my part.  But I think it's an educated one.  The ancient Gentile's options were limited--at least until the end of the first century:  paganism or Judaism.  Post-first-century then the options would've been broader:  paganism or Judaism or the hybrid known as Christianity.  

But during Constantine's reign, to be a Christian meant to worship in the imperial cult (a practice forbidden in Messianic Judaism, see Acts 15).  Furthermore, by the time of Constantine, orthodox Christianity had formalized its anti-Judaic stance (which really began in the second century):

"To understand imperial Christianity's policies toward Jews and Judaism requires an appreciation of its foundational history in the second century, when the younger community fought doctrinal diversity within and persecution without.  During this earlier period, the seeds of orthdoxy's anti-Judaism, which flourished especially from the late fourth century onward, developed and became established." pg. 2 Christian Anti-Judaism: Polemics and Policies by Paula Fredriksen and Oded Irshai

Well, I'm out of time.  Hope this helped someone!