To be a wonderful person you don't need any religion. The early life of Prophet Mohammad (peace be upon him) teaches us this fact. Even when he was not confirmed as God's Messenger, his character was superb. It shows that by cultivating what is good we can be a good person. But there is another part in this. Religion can be the mos powerful motivational tool for human life. And from the life of many companions of Mohammad we can see how Islam as religion transformed them. Many of them were simply barbaric people, hot headed leader and even cruel killer. Those people by religious transformation became one of the most followable persons on earth. So the role of Religion is undeniable. But at the same time, a person has to be a good person by heart. And it can come without any attachment to any religion. It can just come from self-realization, from studying the surroundings and nature.