You can be a person of faith without being religious and being part of a church. You can even be not at all religious and not a believer in God without being against God or against the church at all. Christianity and Christ are not the same things even if they go hand in hand.
A person can believe in God but does not have to believe in everything that Christianity states you should believe. Christianity is filled with nothing but a bunch of hypocritical people who pick and choose when they want to follow the Christian doctrines. This is why many people do not agree with Christianity. Preachers will preach about forgiveness but many will not baptize a child conceived out of wedlock. These same men then cheat on their wives or acknowledge and uphold when a member of their fellowship practice adultery. Reasons like this are why people are against Christianity even though they believe in Jesus Christ as our savior.
Many mainstream denominations of Christianity have very strict views on what the Bible teaches. I do not think that you need to adhere to the teachings of any one church, to think that Christ is a good role model who presents a great many valuable lessons and examples for people.
The Christian religion has been twisted and distorted in so many ways over the last 2000 years or so. This is not the religion Christ preached about. People distort religion all the time for their own agenda and misinterpret the Bible to justify their own means. In addition, half of the Christian holidays have nothing to do with Christ.
You can be not Christian without being against Christ, I am. I'm Agnostic, religion doesn't seem plausible to me or work for me, so I stay out of it. I have nothing against most Christians though, I'm only bothered by the lecturing, vocal minority. If, however, I was outright against the religion, I'd have to be against Christ as well. You can't actively dislike a religion without disliking what is responsible for it.