The fact of an adversary and counterfeits is adequate for me. At the end of the Lord’s Prayer many translations say “but deliver us from the evil one.”
There are other things that point to the veracity of our faith too, though. A significant one to me is that forgiveness looms large – other faiths, not so much. Many others depend on what the individual has to do to appease or please a deity. In ours, it is simple humility, recognizing our sinfulness and being sorry for disobeying our King’s good laws, and accepting the gift of redemption and adoption that we are offered in Jesus.