Which of the following statements are logically equivalent?

Statement 1, Statement 2 and Statement 3 are all logically equivalent.

Statement 1 is the universal affirmative "All saints are materialists".

Statement 2 is its obverse, formed by negating the quality and the predicate.

Statement 3 is its contrapositive, formed by negating and exchanging the terms.

Obversion and contraposition both preserve the exact truth value of the original.

So these three say the same thing in different forms.