anyone can claim anything and it's up to the people to believe whatever that has been said, especially when it all happened more than 2000 years ago.
faith is not necessarily a bad thing as religions r capable of making their's believers better persons. but if misinterpreted, it spells disaster to their's believers. that's y it's called faith, it is what u choose to have faith in. some chose to have faith in the bad ones then that's just too bad lah.
maybe whoever gave your malay moral teacher his religious lessons was the one who couldnt control his urges n decided to get himself a wife, hence telling stuff like this to his students.