Early christians were persecuted for their beliefs. which belief in particular made others suspicious of christians?

Christians especially during the Roman empire, were persecuted mainly because they believed in one God who was the only true God and that Jesus Christ is his son. They refused to worship or bow down to any other god.

Romans and indeed many other communities at the time strongly embraced the worship of many pagan gods and believed that piety to these gods helped to sustain the well being of the cities and people,  a belief Christians did not share nor agree with.

maybe you should ask google for the answer for the question you're looking for

d. migration