The prevailing view used to be that Christianity started out very uniform ("pure"), and became diversified ("corrupted") over time. This makes a basic kind of sense, considering the standard narrative that Christianity derives from Jesus, then the disciples, then Paul, then everyone else. However, in the 19th century, FC Baur argued that the New Testament represents and preserves early competition between "Jewish" and "Gentile" strains of Christianity. Most versions of this position hold that one of the major differences is in the understanding of the person of Christ. More "Jewish" christology tends to be "lower"--that is, Jesus is further removed from divinity, even if he is Christ, and "Gentile" or "Hellenistic" strains have "higher" christology, which brings Jesus farther from the human end of the spectrum and closer to the divine one. I don't like the "high/low" language, but it's industry standard so it's what I'm going to use in this answer. The Gospels of Mark and John are sometimes read as representative of this spectrum: Mark's Jesus is incredibly earthly, perhaps a normal person until his baptism, whereas John's is barely human, to the point of hardly suffering on the cross.

All that is to set the stage for where we are now. You still see some amount of "Jewish vs. Hellenistic" classification, but it's muted. Since the beginning of the 20th century, and especially in the past 50 years, scholars have heavily criticized the distinctions between "Jewish" and "Gentile" as they're usually understood in the discussion, and modern scholarship tends to hold that Jesus worship before the third century was incredibly diverse, with differences marked locally or regionally, and maybe even across class lines, not just ethnically. Higher and lower christologies are still visible, but we're less likely to assign them to Hellenistic or Jewish backgrounds based only on that criterium. Plenty of very Jewish texts have very high christologies, and plenty of low christologies use Greco-Roman cultural assumptions, and plenty of texts aren't so easily categorized.

Unfortunately, part of recognizing this diversity is recognizing the power dynamics that went into selecting the scriptural canon. That is to say, we talk a lot about how diverse early Jesus worship was, but there's painfully little we can say about what that diversity actually looked like, because the winners got to pick what texts survived. LT Johnson was able to declare, in just a couple sentences, both that 1.) early Christianity was incredibly diverse, and 2.) all early Christians had the resurrection in common (Johnson 1998, p. 184). He calls it "a diversity so obvious that it scarcely needs underscoring," and then says, "There exists, in fact, no positive evidence for a movement in the decades after Jesus’ death that was not shaped by belief in his resurrection." Now, an experienced critic can immediately spot the problem: as one of my professors used to say, "Absence of evidence isn't evidence of absence." There could have been lots of people who didn't believe in the resurrection, and their texts just didn't survive or were never written. But in Johnson's defense, we have to work with the evidence we have, and most of the evidence we have attests to belief in the resurrection (and Jesus as the Christ). I'm not aware of anything that is sympathetic to Jesus worship and also explicitly denies the resurrection or Jesus's identification with Christ, with some caveats I'll get to in a second.

Turning to your question, where does that leave us with beliefs about Jesus? Were there any groups that both revered him in some way and also didn't believe he was the Christ? Most often, what's preserved besides the more familiar understanding is a very high christology where Jesus, sometimes for his whole life and sometimes only after the resurrection, is entirely non-human. The Acts of John has Jesus casually shapeshifting from a boy to an old man, while John watches. The Gospel of Thomas isn't explicit on the point, and still has gaps, but as far as we can tell completely lacks acknowledgement of either a birth or a death narrative, and casts Jesus, again, as highly or fully divine. You start running into a theological problem here: if Jesus is divine how can he suffer and die? Mainstream Christianity wrestles over that problem for centuries, and settles it (sort of) with Trinitarianism. Other groups seem to handle it differently. I've heard the argument, though not myself seen it published, that the Gospel of Thomas preserves a tradition that denied the resurrection by denying Jesus's death entirely. The First Apocalypse of James, in the Nag Hammadi library, might imply that Jesus and Christ are two distinct beings, separated at the crucifixion (Schoedel trans.: "I am he who was within me. Never have I suffered in any way, nor have I been distressed."). That reads a lot into it (for one thing, that text doesn't use either name Jesus or Christ, let alone explicitly distinguish them), but it's worth acknowledging the possibility.

On the other side of the spectrum, you get a very low christology, where Jesus is not divine at all, or is made divine later in his life, before or after the resurrection. The Ebionites, as described by Origen and Irenaeus, apparently held that Jesus was a great prophet chosen by God, which is certainly one definition of Messiah, but doesn't impart him any actual divinity. Most if not all versions of Q (the hypothetical proto-Gospel that Matthew and Luke both pulled from) are interpretable on this end of the spectrum. The Gospel of Mark, like I mentioned, can also be read this way, where Jesus attains some kind of divinity only at his baptism, as a fully grown man. Contra Baur, this isn't necessarily a more "Jewish" understanding of Jesus to the exclusion of Greco-Roman culture--the Hellenistic world had been divinizing human beings, especially rulers, for centuries by the time Mark set ink to papyrus, which certainly had influence in the development of Jewish Messianic ideologies, and Mark's Jesus can be read as following a lot of those same patterns. Conveniently, people divinized during their lifetimes have so far not shown immunity to death (barring Elvis Presley, obviously), so if you stick closer to this end of the spectrum, the crucifixion doesn't become a theological problem, at least not in the same way.

The problem with the Ebionites and other adoptionist/low christological sects is that we don't have any direct evidence of them past the first century or so, if at all. Irenaeus and Origen can't always be trusted for their accurate or neutral accounts of other theologies, and "Ebionite" might not even be an insider term. The Gospel of the Ebionites is highly fragmentary, it's entirely preserved in quotes from a non-sympathetic author, and it says very little if anything about these questions. If the heresiologists are accurate, the Ebionite idea that Jesus was "merely" a prophet could be a point of influence in Islamic thought about Jesus, but that gets beyond my ken.

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Johnson, LT. (1998). Religious Experience in Earliest Christianity: A Missing Dimension in New Testament Studies. Fortress Press.

Some other reading (if anyone knows some good recent books on Ebionites, all I'm finding are older essays):

Endsjo, D. (2009). Greek Resurrection Beliefs and the Success of Christianity. Palgrave.

Grant, R. (1990). Jesus after the Gospels. John Knox Press.

Talbert, C. (2011). The development of Christology during the first hundred years, and other essays on early Christian Christology. Brill