Sin and occasion of sin are avoidable or unavoidable, not necessary and unnecessary.

Avoid is the key word and not necessary.

You are correct Neil, unnecessary would also mean there was a necessary.  

And out of charity, it ought to be summed up to "a poor choice of words".

It seems you are correct, holysoulsacademy.  It should be avoidable occasions of sin, rather than unnecessary occasions of sin.  

Most occasions of sin are avoidable, but most occasions of sin are not 'unnecessary'.  

And some occasions of sin are unavoidable, but you can hardly say they're necessary.

Maybe he was trying not to be redundant, because then it would have been, "We should avoid all avoidable occasions of sin."




Perhaps your words are backwards:  you said, "Sin and occasion of sin are avoidable or unavoidable, not necessary and unnecessary," but maybe you were trying to say, "Sin and occasion of sin are avoidable or unavoidable, not unnecessary and necessary."



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