If the door is tight try pushing in around the handle with one hand while pulling the handle open with the other. it helps to take the pressure off the catch. with out looking at it the other common problems are its not unlocking properly try using key instead of the electronic switch or could be gummed up with greasy dirt or rust which may need gentle persuasion. Thinking about it cant remember which end off the door is the catch may need to push on the opposite end off the door while you pull the lever. give both a go and when open give a good lube up

G'Day-My Dad works for Ford/Mazda...same van just different badges,so I hope this advise is helpful.
First of all he say's that a 2002 Econovan is not new
Next-the sliding doors have problems with the female and male matching locks/strikers,for some reason they where out,which causes the sliding door to sit out. You have to look very closely and supply pic's of the female and male locks.
If that is not the problem,the top and bottom rollers are most likely worn out.The rollers fit into a sliding bracket,if they are worn the rollers jump out of the bracket,also causing the door to sit out.