Jesus said to his disciples: "Things that cause people to stumble are bound to come, but woe to anyone through whom they come. It would be better for them to be thrown into the sea with a millstone tied around their neck than to cause one of these little ones to stumble. Luke 17:1-2
"Who is the liar? It is whoever denies that Jesus is the Christ. Such a person is the antichrist--denying the Father and the Son."
"You believe because you have seen me. Blessed are those who believe without seeing me." John 20:29
"Truly I tell you, unless you change and become like little children, you will never enter the kingdom of heaven" Matthew 18:3.
They first believe he is the messiah, before they check the claims. Thus they are bias in their judgment
"He that answers a matter before he hears it, it is folly and shame unto him" Proverbs 18:3
"Do not accept a bribe (Heaven), for a bribe blinds those who see."
The Christian faith is based on the scriptures of the Bible and the Bible does state that Jesus is the Messiah. They follow the religious book that represents their faith and debating whether they should follow their own faith is not as intelligent of a debate as some would think.