When to court the other day - such hypocrisy

I went to court the other day and upon entering the witness stand to give evidence was asked to swear an oath on the Bible. At the time i made a fuss about how this is silly considering the Bible warns about not giving oaths, but i did it anyway. Now that i think back about it, why does the court even use a Bible when the judiciary by and large does not even keep the ten commandments. I am not judging them for accidentally sinning, we all do that. But every weekend i am quite certain many of them wilfully break the sabbath.