Is this sentence natural? Or how would you say it?
Receive with matureness everything that happens to you.

Question

Is this sentence natural?  Or how would you say it?
Receive with matureness everything that happens to you.

Answer

I would personally say:

Receive with maturity everything that happens to you.

Answer

Well, your sentence sounds poetic!  But if I, personally, were to say it naturally, I would probably say, "Be mature with everything that happens to you."

So, what you said is not wrong, but I would not say it is quite "natural" for a native English speaker.