A lot of writers struggle with deciding what to do for money. Writing is passionate, fulfilling and exciting career path, but it's not the most fruitful. Even if you're published, it's no guarantee you'll make enough money to support yourself. So do you get a day job, which for the purposes of this post refers to a non-writing related career, to pay the bills or live lean and write full time.
Pro: You have a Steady Income you can rely on.
Con: Why Do You HAVE To Write if it isn't earning you money?
Obviously, day job are great for the money. And you need money to live. There are alternatives though. You can be a freelance writer, you can get a job in a writing field, you can marry rich. You have options. But at the end of the day, getting a regular, cubical job will most likely give you the best salary. The problem is, though, if you don't have to write to make your money, how motivated will you be to get that book written when you get home from work everyday?
Pro: You can reserve your creative energy for writing.
Con: Most of the day, you're doing work you're not passionate about.
It's possible you'll have a day job that allows you to be creative, but most likely you'll have a job that doesn't require much creative input. This is great for your writing, because you'll have more creative energy and inspiration left to work on your writing after work hours. But that does mean that you may find some of the work you're doing at your day job to be mundane or unfulfilling.
Pro: You Have a stable 9-5 schedule.
Con: Writing Time Is Limited to Evenings and Weekends.
While freelance work or full-time writing allows you some flexible scheduling, it also opens the door to overscheduling or underworking. A day job will offer you a stable 9-5 schedule, or at least one that you can depend on. That does mean though that this is a large block of time everyday that you won't be able to write. This means if you want to dedicate time to your creative work, you'll need to cut into time you may want to spend relaxing or hanging out with friends or family.
There's no easy answer to the day job vs full-time writing debate. For every valid pro, there's an understandable con. So much of your decision will come down to your personal situation. What works best for one person won't be possible for the other. At the end of the day, though, we're all writers and we're working towards our goals in our own time.