I've recently been invited to a Maitreya Buddha's Temple. They are required to held a ceremony if you want to join. So I do a little research and found out the name of their teaching is actually "Yiguandao". They stated that this world/earth is created by Eternal Venerable Mother (Wusheng Laomu) source which I find contradicting to Gautama Buddha's teaching where there is no supreme creator source. And some other factors I find even more contradicting to Buddhism as what I know.
All I need to know is whether this teachings is something different from true Buddhism Teachings and where did this teachings come from?
And If they are not the same, why do the use Maitreya Buddha in their teaching?