Correct, and to mind ones attitude towards them knowing that your election is neither something you can take credit for, nor that they cannot also have, should they believe.

Going full hostile, calling them Satan worshippers, etc, fails on two counts; it's a) incompatible with humility on your part and the instruction regarding your attitude towards them,

and b) incompatible with them being like natural branches that have been broken off for their disbelief but are regraftable, and the bit earlier where it says God has not (collectively) rejected his people.

If Paul was to describe Satan worshippers, the reason for their non salvation wouldn't be described merely as 'unbelief'. Paul is pretty blunt in his epistles when he considers something demonic or of the devil.

There is a third way in which it fails, which is that charging in and calling people Satan worshippers is among the world's worst conversion strategies, but that's a practical matter rather than a principled one.