is it ours or not?

We were offered an expensive workout machine by a couple that were our friends. They said that they got it at a yard sale for under $20, but never used it. We asked SEVERAL times if they were ok with giving it to us, and even offered them the same amount they paid, but they refused and said we could just have it. Now the wife is not working, is bored at home and wants it back. They now claim that it was only lent to us not given. They are even threatening us with being arrested for possesion of stolen property. IT'S BEEN 4 MONTHS!

If it was a gift there is anothng they can do; if they sue you will testify it was a gift.

Thank you very much. We REALLY appreciate your help. I guess from now on we should ask anyone, including good friends, to sign a paper with their intentions if they give us something (especially like this elliptical machine)? Or is that not legally valid unless notarized?
Again, thank you very much.

That would also be valid even w/o the notary as an agreement.