Door sags and isn't aligned with the striker
 

What do I need to replace to fix my door, the only way I can close it is by lifting it as it closes.

sometimes the bushings and hinge bolts wear to cause a droop. They are a cheap fix from most auto parts stores to get new pins and the plastic bushings (2 for each hings) to replace them. Open the door and lift it up and down to see if the that is the area of problem.

Bushings wear and the door drops. Fairly easy to fix. If you don't have time to go find them you might try and put a washer between the bottom hinge and the frame at each mounting bolt. It might be enough to make it close. If it is a lot, try two washers at each bolt. Mark the hinge location before you move things around. Loosen both bolts but just remove them one at a time so you don't have to steady the door so much. Put a screw driver behind the hinge, and pull one bolt, slide in the washer and start the bolt in but not tight. Then do the other bolt and then tighten them both in the marked location. Then you can get the bushings when you can. Good luck with it.

http://www.lincolnsonline.com/article45.html

Here's a guy who showed pix and detailed instructions on how to fix his. I looked up the parts online and the new pin/bushings cost $4.98 or something at autovalue (for years 87 to 96 I think) and the part number is 38410.

Same problem on my truck, but from people trying to slam the door shut, the striker basically broke. That part # is 38448 and it cost around $8.00

~Matt