Difference between “May” and “Let” in prayers

Question

Is "Praise be to the God and Father of our Lord Jesus Christ" a short form of

1. “Let praise be to the God and Father of our Lord Jesus Christ, ----“?
2. “May praise be to the God and Father of our Lord Jesus Christ, ----“?

Likewise, “Thanks be to God.”

1. Let thanks be to God.
2. May thanks be to God.

Blessed be the God and Father of our Lord Jesus Christ, the Father of mercies and God of all comfort,

1. May the God (and Father of our Lord Jesus Christ) be blessed
2. Let the God (and Father of our Lord Jesus Christ) be blessed.

If my guess is right, is there a meaning difference between “May” and “Let”?

Answer 1

Let me start off by saying that I have no theological background.

With that out of the way, the key difference between let and may in this context is:

• Let - is a statement acting as a command
• May - is a statement acting as an invocation or request

So, in a statement "Let us give thanks to our God", this is a command to the congregation to give thanks to God. The speaker (presumably a reverend/padre) is instructing the congregation on this point, with the use of "let".

On the other hand, "May the God ... be blessed" is a request to a higher power to provide blessings to God. And as humans, all we can do is make such a request.