Marie Osmond is dishing all about her new album -- only to ET!

She tells us she's making her "very first inspirational album" which will include opera pieces, choirs and strings.

"I really wanted to do it because God has been so good to me -- especially over this last period of time -- to just help me find peace in my life and happiness...."

You can catch Marie with her brother Donny on stage at their show at the Flamingo Hilton in Las Vegas!