I know mcguffins are a generally included in most games, at least thats what i've seen. I'm just here to ask if you guys would discourage the use of them. I'm curious to know peoples opinions!

It isn't required to have an item of mysterious consequence. They appear in a many games and some have none. You shouldn't feel the need to add one or to avoid adding one. The best are when the PCs think some item is a mcguffin when you didn't design it that way. 

The term gets thrown around a lot in many different ways, so let's start with definitions.  

I call something a MacGuffin when it starts the plot moving, but the actual nature of the thing is indeterminable and basically irrelevant to the plot, or only one side ever actually knows what it is.  When someone asks "what's in the chest?"  and the guy says "that's not important, all you need to know is that you must go to any lengths to retrieve it and bring it to me," that's a MacGuffin.  Sometimes you find out that the Maltese Falcon is a worthless fake (spoiler alert) or that Rosebud is a sled, or that the shiny briefcase in Kiss Me Deadly is full of atoms or something.  But the audience doesn't know for most of the story and doesn't particularly care by the end.

When the guy says "if Sauron gets that ring back, he'll be restored to full power.  He'll be able to control the three elf rings.  And the force that had to be assembled to stop him 10,000 years ago can never be assembled again.  Therefore, he will gain complete control over Middle-Earth and you and your descendants will be doomed to live under the yoke of his tyranny unless we can throw that thing into a volcano.  Also it has a personality of its own and maybe even a few lines of dialogue," that's a plot device, but I wouldn't call it a MacGuffin.  When two guys are trying to win the F1 Championship, the championship is the premise, not, imo, a MacGuffin.

I don't mind them, once in a while.  The fact is, a good MacGuffin causes the audience (the players) to project their own goals onto it.  That's why they're "the stuff dreams are made of."  But I think most players prefer a more concrete goal or set of stakes.  I would discourage overuse.

Those are great points, thank you for sharing! 

Now I do want to ask a question of you, in a current game I'm about to start I'm thinking about including a conflict with followers of some god. To introduce them I've essentially came up with the idea that the PC's will at some point come across some artifact that can let them go to another plane or cast gate once a month or something like that not quite sure on the specifics yet. But the idea is that the BBEG will want the artifact to open a gate and allow their god to fully come into the world, pretty basic stuff. I just wanted to know if that seems like a decent enough idea to you or if it may come across as boring or something.

It's a good starting point.  As you say, it's familiar stuff, but familiar isn't bad, it's just execution-dependent.  And it gives you the chance to add little tweaks and twists.  The artifact sounds like a cubic gate.  Can the boss and the players go back and forth to the god's plane and only the god is trapped there?  Can the players use the plane shift feature to lead the bad guys on a multi-planar chase scene?  If the party uses it, and then the bad guys get it right afterwards, the party will know that they have a one-month countdown until the bad guys gate their god in.  Deadlines are good.  I think in this particular case, the artifact sounds like it could be a lot of fun for the PCs to play with.  Therefore, I'd make it less of a MacGuffin.  If you just wanted some old man to say to them "The Gem of Amet-Ghaz!  It must be kept from the bad guys at all costs!"  and they never use it or learn what it does, they just know that the bad guys can't have it, that could also work, but you have to have something else to hook the players with instead.

MacGuffin originally meant an "unknown plot objective which you don't need to choose until the story is complete." Because it is unknown, a MacGuffin's nature is essentially irrelevant to the story. You could change it to something else and the story would be the same. Hitchock often used MacGuffins... their use did not make his movies less outstanding (Hitch is my favorite director of all time). A famous Hitch MacGuffin is the $40K that Janet Leigh's character steals from her office that triggers the whole plot (she flees with it, ending up at the Bates Motel, leading to the most famous shower murder scene of all time). It doesn't really matter what Leigh takes from the office in Psycho, just that she stole something and wanted to get away with it. Was it bad that this is the case? Did it make the movie worse? Consider, Psycho was named by the American Film Institute back in 2000 or so as the #1 thriller of all time.

In story writing, sometimes you just need to get on with the story so you can get to the end, as Hitch might have in Psycho (or maybe the original novel's author did -- I've only seen the movie, not read the novel). You know that Leigh is going to steal something from her workplace, but 99% of the story is about the hotel, the murder, and Bates, not the workplace or the theft, so you just put that aside and move on, deciding what was stole and where she worked later, after you have the important bits worked out.

In running an adventure, however, there isn't any ability to revise or re-write the beginning after play begins, like you can do with a novel. You can't film the first scene last and then, in editing, put it at the start of the movie, like you can with a film. You can't get to the end of the adventure and then after the players defeat the BBEG, say, "You know, that wand we started with rally should have been a scepter, let's change it to that and re-play the opening scene." So you really need to know what the item is, what is nature is, how it works, and why it is important, before you start play with the players. (You don't need to know before you plot out the adventure, though... you can do that and then back-fill, as long as you back-fill before the first session.)

Now, if you have an object whose nature is known, defined, and relevant to the story, like the One Ring, you actually don't have a MacGuffin -- you have a plot device. Plot devices are also highly useful, as Lord of the Rings proves, in getting a story going and moving it along. The Ring's nature is not only not irrelevant, but is the key to the whole story. If the Ring had a different nature, none of the LOTR actions would have occurred at all. Tolkien even shows us this is true by presenting us with Nenya, on Galadriel's finger, one of the Elven rings, and that ring, which has a different nature, did not trigger the same storyline that the One did. Thus, LOTR shows us not only the difference between a MacGuffin and a plot device but it shows us how to make an excellent plot device. The device's nature is not only "relevant" to the story but crucial to it. The Ring becomes almost like a character, having relationships with the different characters and even "convincing" them to act contrary to their own stated goals and desires.

Neither a MacGuffin nor a Plot Device are objectively bad -- they are used in storytelling because they work. However, I would say in planning out an adventure, you're probably better off going with a plot device whose nature is known and relevant before the first session begins, than a MacGuffin. Because unlike in writing, we can't go back (normally) and re-play old D&D sessions once we have figured out "what the MacGuffin is."

what im currently thinking is that the players (who have expressed interest in obtaining a sky ship, this is a steampunk setting) will at some point encounter a ship that is rapidly shifting in and out of planes and after getting on board or the ship having a critical failure and crashing they would explore it and fight off some magic corrupted humanoids and find out that the people had attempted to integrate the item into the ship thus damaging it and limiting its uses. After sometime has past when they acquired it they will most likely start to be hunted down by paladins of the god, all of which would specialize in illusion magic and the BBEG or the villain of that particular story will be a beefed up illusionary domain cleric. i feel like the antagonists possessing the power of illusion would make for some interesting scenarios. Im not entirely sure what the consequence for losing the artifact and allowing the god to enter the world would be but i would imagine it to be a powerful illusion that could alter the inhabitants of the worlds minds, like i said i haven't thought of that part yet. thats just what came to mind while typing this. 

Then by all means, keep typing.  It sounds like you're getting into a productive groove.  A lot of weird and interesting stuff comes out at those times.

Not all followers of a god need to be from the religious classes, keep in mind. Anyone can be a zealot. An illusionist wizard, or a rogue/ranger/monk who's very good at hiding (camouflage is a kind of nonmagical illusion) come to mind, but any class works. And don't forget trickery domain clerics.

RAW, paladins don't get illusion spells. And paladins don't even necessarily serve a particular god anymore, just a series of oaths. I don't think it would be game-breaking to add a couple illusions to their spell list, and you're the DM, so its well within your rights. Just be prepared for players that might whine a bit when they meet someone who can cast Major Image and also smite. There's Eldritch knights that get spells from the wizard list and could therefore have illusion spells RAW. Or you could fairly easily homebrew some sort of holy warrior that follows this god, mostly so your players don't complain that you're not following "the rules."

Your comment about them putting a planar gate into a ship made me think of Star Trek: "What does God need with a starship." Maybe the god isn't a god, just someone who's trapped somewhere else, and who managed to trick others into thinking its a god.

Also, you might want to consider adding in a ticking clock element. Otherwise it turns into the players playing keep away with the gate device indefinitely. A classic version is it only works properly under certain conditions (and that's why the ship integration failed in the first place) and those condition are happening soon-ish and won't repeat for 5,000 years. It gives a reason for why the bad guys are so amped up about getting this thing back right away, and gives players a clear goal and timeline.

Also, I can't stress this enough, make sure the players can lose. A story has to have stakes, and if they realize the whole thing is on rails and you'll give them chance after chance it undercuts the whole narrative. Allow them to fail, even in the big climactic fight at the end. Which then sets up campaign 2 in a different version of the world after the BBEG has succeeded and now new characters want to put things right.

The Paladins also don't have to be actually from the Paladin class. They can just be monsters with special abilities, actions, reactions, and legendary actions. Nothing says that you have to have the monsters/NPCs follow the same rules as a PC who is making up a full character of a character class. The official D&D monsters certainly don't follow those rules.