There's quite a lot of Jewish and Christian influence in the so-called 'Greek Magical Papyri' - a modern collection of pagan magical spellbooks from Roman Egypt (mostly later than the 3rd century AD). These texts take inspiration from lots of different religious cultures - mostly Greek and Egyptian, but also Mesopotamian and, as I said, Jewish. The angels, prophets, holy men, alongside the Jewish God appear as sources of magical power or knowledge. Take this spell for example:

PGM LXXXIII. 1-20 *For [fever with shivering fits]: ' "GOBA . . . s . . . MO . . . NOUSBA . . . EIEGE . . . OSARK. . . AUSE fever with shivering fits, I conjure you, MICHAEL, archangel of the earth; [whether] it is daily or nightly or quartan fever; I conjure you, the Almighty SABAOTH, that it no longer touch the soul of the one who carries [this], nor [touch] his whole body; also the dead, deliver, . . . the disrress IDOT . . . YGRSBONOE. . . . " "He who dwells in the help of the Most High shall abide in the shadow of the God of heaven. He will say of God, 'thou art my refuge and my help; I will put my trust in him." "Our Father who art in heaven, hallowed be thy will; our daily bread."' "Holy, holy is the Lord SABAOTH, heaven is full of justice, holy is the one of glory."' ''ANIAADA . . . IA, MIGL' of lords, Abraham Isaac Jacob ELOEI ELE Solo- mon(?) I ~ABAOTH OBL. . . .

There are obvious names invoked here that would be familiar to any Jew or Christian, and also some quotes from scripture. However, their random nature and the fact that the lines from the Lord's Prayer are garbled suggests this wasn't written by someone particularly familiar with the Bible. There's no connection to any specific part of Jewish or Christian theology - God, his angels and prophets are merely being invoked as sources of supernatural power that can be harnessed to produce the desired effect, which in this case is the curing of a fever.

Elsewhere, Christ's reputation as an exorcist is combined with more pagan elements in a spell for driving out demons:

PGM N. 1227-64 *Excellent rite for driving out daimons: Formula to be spoken over his head: Place olive branches before him, I and stand behind him and say: "Hail, God of Abraham; hail, God of Isaac; hail, God of Jacob; Jesus Chrestos," the Holy Spirit, the Son of the Father, who is above the Seven, who is within the Seven. Bring Iao Sabaoth; may your power issue forth from him, NN, - until you drive away this unclean daimon Satan, who is in him. I conjure you, daimon, whoever you are, by this god, SABARBARBATHITH SABARBARBATHIOUTH SABAR- BARBATHINETH SABARBARBAPHAI. Come out, daimon, whoever you are, and stay away from him, NN, now, now; immediately, immediately. Come out, daimon, since I bind you with unbreakable adamantine fetters, and I deliver you into the black chaos in perdition." Preparation: take 7 olive branches; for six of them tie together the two ends of each one, but for the remaining one use it like a whip as you utter thc conjuration. Keep it secret; it is proven. After driving out the daimon, hang around him, NN, a phylactery, which the patient puts on after the expulsion of the daimon-a phylactery with these things [written] on 1 a tin metal leaf: "BR PHOR PHORBA PHOR PHORBA BES CIIARIN BAUBO TE PHOR BdRPHORBA PHORBABOR BAPHORBA PHABRAIE PHdRBA PHARBA PHRPHOR PHORBA / BOPHOR PHORBA PHORPHOR PHORBA BOBOR- BORBA PAMPHORBA PHORPHOR PH~RBA, protect him.

A good example of a syncretism including a mixture of Christianity and Judaism is Manichaeism, which also includes many elements of Buddhism and Zoroastrianism. The religion was founded by the prophet Mani, who declared himself one in a line of prophets including Zarathushtra, Gautama Buddha and Jesus. One of the most famous practitioners was Augustine of Hippo prior to his conversion to Christianity.

This is the most relevant writeup of mine: Mani & Manichaeism

Unfortunately I'm not that read up on how exactly Manichaeism manifested in the Roman Empire, but it certainly existed and was a syncretism including Judaism and Christianity.