Learn English – “Positive” synonyms for ‘problem’ or ‘worst’

First of all some people question the existence of perfect synonyms:

Some lexicographers claim that no synonyms have exactly the same meaning (in all contexts or social levels of language) because etymology, orthography, phonic qualities, ambiguous meanings, usage, etc. make them unique. Different words that are similar in meaning usually differ for a reason: feline is more formal than cat; long and extended are only synonyms in one usage and not in others (for example, a long arm is not the same as an extended arm).

So, the context is important, and now, for the Almighty, yes its primary meaning according to AHD is

Almighty, n.

God. Used with the.

However, do not forget how strong and different is the context of religion and how the word God is in this sense overloaded with different meanings.

From Wordnet you have

Noun 1. God Almighty - terms referring to the Judeo-Christian God

So, yes, in context of Judeo-Christianism at least, the Almighty is synonym with the God. For other religious contexts you might want to see an article on Names of God.

EDIT: As for usage, the Almighty means God, however if you use it as adjective, as in (very well known) example:

The almighty dollar, that great object of universal devotion throughout our land." [Washington Irving, 1836]

the meaning is metaphorical, so it still means god-like, divine. So, the question is what kind of usage are you talking about?

You didn't specify beyond the combination of the two words "at worst."

There's another idiomatic expression that goes: "...at best and...at worst." I suppose this counts in your question.

With the particular structure above, I can make sentences in all sorts of Tenses.

Present: "Entrepreneurs are difficult at best and abrasive at worst."

Past: The entrepreneurs (at the conference) WERE difficult at best and abrasive at worst.

Future: The entrepreneurs (at the future conference) WILL BE difficult at best and abrasive at worst.