Christianity (and other religions) were good in theory and miserably failed in practice (something like communism).
It depends how you assess failure and success.
Let me illustrate with the life of Elvis Priesley. From the world's point of a view he was a very successful musician. Crowned by his fans as the King of Rock'n'Roll, many would die to live the life he lived even for a moment.
Six weeks before he died, Elvis Presley was asked by a reporter, “Elvis, when you started playing music, you said you wanted three things in life: You wanted to be rich, you wanted to be famous, and you wanted to be happy. Are you happy, Elvis?”. Elvis replied, “No. I’m as lonely as hell.” He said that a long time ago he had rejected his only true friend, Jesus. A preacher who had prayed for him said, "If he were offered his salvation tonight, he would probably say, 'No thanks, I'm on the top.'" Eventually he died of drug overdose.
So you see, it was the same life seen from two different perspectives, one as a success and another as a failure.
Christianity wasn't meant to change the world but the inner life of a person. Jesus said that he 'didn't come to bring peace to the earth'. He said 'a man's enemies will be the members of his own household', let alone world peace. In fact he prophesied that in the end sin will abound to such a degree that he would have to destory the earth as he did in the days of Noah.
As I mentioned in a previous post, Christianity is misrepresented especially in the west with all its denominations. This is because many who profess to be Christians are not. It doesn't matter to me if they have some great position in the church. Jesus spoke of the Pharisees (Jewish religious leaders) in a very harsh manner warning the rest of their hypocrisy.