Would you live your life in any different way if you believed in an afterlife?
I think the main influencer on that would be whether or not you
also believed that your actions in
this life would have any effect on your afterlife.
For example, suppose Jesus tells you that you're going to heaven no matter what you do, because God loves you. In that case, you have no reason to change whatever it was that you were going to do anyway, just because you've learned that heaven is real.
On the other hand, if Jesus tells you that if you do bad things you'll go to Hell, but if you do good things you'll go to heaven then if you were a rational sort of person you might be incentivised to do more good things and fewer bad things. But then again, people are notoriously bad at making good choices in the short term for a uncertain or non-specific potential long-term gain; they will often be tempted to go for one cookie now rather than 10 cookies at some future date. There is, in fact, some data on this. Christians who believe in the afterlife of heaven and hell, for example, are no less likely than atheists to commit crimes as a result. In fact, they even might be, on average,
more likely than atheists to commit crimes.
Finally, if Jesus tells you that if you strap explosives to your body and kill yourself (and maybe a whole bunch of other people at the same time) in His name then you'll go directly to heaven and live in paradise with Him forever, then you might be motivated to end your life as quickly as possible, because the promise of heaven sounds really neat and much preferable to this mere worldly existence.
In practice, of course, none of us
know if there's an afterlife - or what Jesus (for example) actually said or wants. Given this fact, it doesn't make a lot of sense to change how you live your life, based only on a belief system for which you have no good evidence.
I suppose that some people might benefit personally, in terms of a greater sense of contentment or similar, from their faith-based belief in an afterlife, but whether or not that occurs - or whether it is beneficial or detrimental to the individual - will usually depend on the nitty-gritty of what is actually believed. Some people, for example, go through life carrying a very real (to them) fear of going to Hell, which inevitably impacts on their ability to fully enjoy life.
Would you be less afraid of dying? More afraid? Or the same..
Again, it depends on the details of the belief.
Suppose that the belief is that
everybody goes to a Hell, regardless of what they do in life, because "we're all sinners" or something. Anybody who honestly believes that will be more afraid of dying than somebody who doesn't believe it - or who believes we all get Paradise after we die.