My Macquarie Dictionary, albeit from 1981, has the following definitions.
1 – judgement or belief resting on grounds insufficient to produce certainty.
2 – a personal view, attitude, or estimation: public opinion.
3 – the expression of the personal view, estimation or judgement: to give an opinion on tariffs.
4 – a formal or professional judgement, expresses especially in law: counsel’s opinion.
5 – a judgement or estimate of a person or thing with respect to character, merit etc.
6 – a favourable estimate; esteem.
– obstinate or conceited with regard to one’s opinions; conceitedly dogmatic.
1 – pertaining to, or of the nature of a dogma or dogmas; doctrinal.
2 – asserting opinions in an authoritative, positive, or arrogant manner; positive, opinionated.
1 – a system of principles or tenets, as of a church.
2 – a tenet or doctrine authoritatively laid down, as by a church.
1 – the act of judging.
2 – a judicial decision of a cause of law.
3 – ability to judge justly or wisely, especially in matters affecting action, good sense, discretion.
4 – the forming of an opinion, estimate, notion or conclusion as from circumstances presented to the mind.
5 – the opinion formed.
6 – a misfortune regarded as inflicted by divine sentence, as for sin.
7 – the final trial of all mankind, both the living and the dead, at the end of the world.
Okay, so what did you get from that?
I got that opinions and judgements are pretty much the same thing. You judge when forming an opinion. So then you are opinionated when giving the opinion. Your opinion is your own thought, feeling, belief, attitude etc.
And if we have them and stand by them we will all go to hell for having them when the world ends.
Pretty simple and easy to understand.