Well, even though one may say there is only matter in motion, will it change anything? Will it cut off my feelings? It's like Parmenides who wrote two books, The Words of Truth and The Words of Opinion. In the first he presented the idea of absolute monism which is very close to Hindu Sat-Chit-Ananda. But the sun remained rising every morning for him as it had done before, so he wrote a book of observations over the nature, his second book.
Since my childhood until the age of sixteen I was an atheist. So, was it a hindrance for my spirituality? The hindrance was not atheism/materialism but my adherence to it. At the age of 15 I read a novel Resurrection by Tolstoy which caused a spiritual earthquake in me. Even though I was a materialist.
Materialism and idealism are two forms of explanation of reality, two ontological theories. The reality is independent of them. And if love, peace, Nirvana or whatever thou mayest call that is the highest happiness, the only happiness, it will be the same to any person.
The problem with materialism/evolutionism is that it sometimes going make deductive conclusions: "Human is animal. We know what is good for animals. Therefore what is good for animal is the happiness of Man" instead of trying to find what is good for Man without any mind-built theories.

What do you mean by "we are already free"?

We are free to be happy, that was my point. There is no need in special state, social or political system for this. When one knows that material conditions have so little value, when he ceases to seek happiness in a certain arrangement of things, there comes freedom. Why do I call that freedom? Because here the desire disappears, and when there is no desire, nothing is done against my will, that is I am free.

Okay, thanks for the explanation.