It is so easy to say, I grew up with this person, or this person has been with me at work for x amount of years - but ya'll, just because you've known someone for a long time doesn't make them the best fit in your party.
I have some very good friends who I've known since grade school, we've gone through tons of milestones together, we keep up with each other and when we chat its like no time has passed and i know they would be there if anything ever went down...but that doesn't mean they are the best person to support me and my happiness through a year+ long journey of an experience that is quite actually all about you and your growth. If they aren't in a good place in their life, or they are moving a million miles a minute in their own life, it may not be the best time to ask them to be all about you and your life.
Let me break it down further...
you can be the very best friends with someone for regardless a number of years, but if they are dating someone who makes them a different person... they don't need to be in your wedding because thats not the person you are friends with.
you can talk to someone every single day...but if they are dealing with infertility issues (or other major emotional situations), they are not in the headspace to be in your wedding and celebrating your happiness.
you can have a girls night every week on their couch...but if they are having financial issues, they do not need to spend money being a part of your wedding and they can enjoy the day with you other ways.
I'm gonna take a step back
though.... because it 1000% depends on the person and how they handle said situations above on a regular basis. You need to be honest with yourself and ask how they handle stress, what is their personal situation, what do i love about them and are they still true to those things?
Questions to ask yourself when contemplating your wedding party:
does this person mean something special to me?
is this person reliable?
is this person in a stable headspace to help me in my happiness?
will this person help make every event leading up to the wedding & wedding weekend exactly what i want it?
can this person enhance my wedding experience?
will this person let the celebrations be about me and my fiancé?
It may sound harsh...but you have a lot of people come and go in your life and just because you feel like they should be involved in your wedding party isn't a good enough reason to have them as part of your wedding party. This is the time to be selfish. This is the time to be the happiest you've ever been and if someone is going to jeopardize that, they don't need to be involved in the nitty gritty of it.
What if someone asks why they aren't in the wedding party?
first off that's rude... and they are just making it about them instead of about you, so good decision not asking them.
second...a good way to avoid this is to be proactive. If you choose not to have someone in the party, ask them to do a different job - walk grandma down the aisle, give a toast, etc.
If this person is dealing with a personal issue and you are on the fence, have a heart to heart...lay everything out for them, tell them it's your time to be selfish, and then ask if they can handle the responsibility.
What if I already ask someone to be in the wedding party and I change my mind?
First, ask yourself why you changed your mind.
Is this because of something they did? Great! Talk to them about it before giving them the boot. You asked them for a reason, so give them a chance. Take the conversation to heart and then make a decision.
If they didn't do anything and you still changed your mind...ask yourself why you made the change and really decide if it is worth losing a friend over.
Wedding Party Gifting Tip:
If you want a member of the wedding party to wear something special on wedding day - don't gift it to them until wedding weekend! That way nothing is lost or forgotten!