Please help me. My son will not sleep in his own bed and he is now three. Please help me to get him to sleep in his own bed.

You kind of have to make him do it... put him in his bed at bedtime and leave him.. if he goes to you bed, pick him up and put him in back in his bed. Don't GIVE IN. it may be a ruff few nights but eventually he will stay.

Yep, who is the parent, you merely make them sleep in their own bed

They are right. Although I do not agree with letting the child cry themselves to sleep... And don't forget how quickly they grow up. Pretty soon you will be longing for the times when he would sleep in your bed with you.

Disagreeing with your parents is half the fun in being a small person! Parents win, though, because they're bigger and in charge.
You have to make sure that the child falls asleep and wakes up in their own bed, regardless of what happens in between.
How lovely to have a three year old - good luck with this battle!