In an earlier post I referred to the Akeptous Inscription which contains the words "...to God Jesus Christ" and described it as a rather perplexing inscription which reflects a high christology that didn't exist until the fourth century. Since then I have done some additional research on the inscription, and find that both the translation ("God Jesus Christ") and the dating of the mosaic (230 AD) were only based on a preliminary publication.
Since the prliminary publication (2006), there has been a subsequent article in The Expository Times, 2008, on an assessment of the significance of the "ancient church at Megiddo".
The writer, Edward Adams, Professor of New Testament Studies at King's College London, reports that the Akeptous Inscription which was first translated as
"The God-loving Akeptous has offered the table to God Jesus Christ as a memorial"
could also be translated as
"Akeptous, the God-loving, has offered the table to/for God, a memorial to/for Jesus Christ."
Adams notes that there does appear to be a space between "God" and "Jesus Christ" but suggests "it seems more natural to take all three words together". Quite clearly there is more than one way to translate this inscription, and I suggest it is more natural to read it distinguishing between God and Jesus Christ, befitting the second and third century, than the reading indicative of the high christology of the fourth century.
The other aspect discussed in the Expository Times assessment is the dating to the year 230 AD. Adams writes :
Other experts, however, have contested the proposed dating. Reacting to the initial announcement, Joe Zias, a former curator of the Israel Aniquities Authorities, doubted whether the mosaic could be pre-Constantinian. In his view, the building is most likely a Roman building adapted for Christian use at a later date.
Gaianus' benefaction [another inscription which said that Gaianus, a centurion, had made the pavement at his own expense] is felt to be problematic for a pre-Constantinian dating of the church. Zias doubts that a Roman army officer of the third century CE would have been so foolish as to advertise his Christian faith in this way....By making (what amounts to) a public declaration of his allegiance to Christ on army or state owned property, Gaianus would be inviting the kind of religious conflict, with potentially fatal consequences, that others took care to avoid. Gaianus' profession of faith would thus be unusually daring for a military officer of this period, which seems to make it a difficulty for a third-century dating of the church.
So the dating is quite important. If the dating advanced by Tepper (230 AD) is correct, it would be the earliest example of a Christian structure, the floor inscriptions would rank among the oldest epigraphic data for Christianity, the Akeptous Inscription would offer the earliest epigraphic occurrence of nomina sacra and one of the earliest inscriptional references to Jesus Christ, and the mosaic floor would be a very rare instance of a pre-Constantinian Christian mosaic. This makes Tepper's dating all rather unlikely, although not impossible.