It has been said and i've heard and read that God, is a Jealous God...but how can this be?

I've read in bibles and heard from people claiming God, in some situations , being a Jealous God? This confuses me, how can god have jealousy? Isnt jealousy a sin? or something that leads to worse acts that truly are sinister? How can God portray this attribute, if its a sin? Can god really be almighty to get away with being jealous or having sinful ways? Arent those the ways or Satan? I'm rather puzzled at this notion referred in the bible at some parts with God being a Jealous God.