If your faith is strong enough as to not leave any room for doubt, this topic is not for you. Please move on and pray for the rest of us.
If your faith isn't strong enough as to reject the question "what if we're wrong about our beliefs?", you're invited to answer how often and how intense your struggles with doubt are, and how you handle the feeling that there's a possibility that we, Christians, might be wrong about our beliefs.
Atheist writer Richard Dawkins was asked what he would do if he found out that his lack of belief was wrong and he were to meet God in the afterlife. His reply is in an interview somewhere on YouTube. Now, let me ask you a similar question: what would you do if, in the afterlife, you were to find out that our beliefs were wrong because of satan's trickery or for whatever other reason, and that eternal punishment awaits us due to having lived according to a wrong set of beliefs?
Considering the lack of applicability of Jesus' promises in everyday life, as well as my poor health, I don't know how to cope with the possibility that I might be following the wrong path.
Re-reading this I had a few more thoughts.
Firstly, my personal opinion (which is arguably worth what you paid for it) is that anyone who claims to never doubt is lying. I know it's ultra trendy among some of the silly charismatic fringes of the church to act as if everything is permanently wonderful and that nobody ever doubts anything but in my experience all that achieves is lots of people who feel utterly lost when they do start to have doubts.
One thing with life is that almost nothing is guaranteed. It used to be said the only certain things in life were death and taxes. Years ago a salesman I was talking to said "there are two things that are certain - my mother met my father and one day I'll die". In this age of IVF and donations people can't even be sure their biological parents ever met each other, leaving death (and taxes) and the only certain things. Whatever the decision we make we have to consider the possibility we made a bad decision, or even a less-than-perfect decision. When I moved into my current house I knew it had a lot going for it, and that it had downsides. When I started renovating it I knew the end result would be something I'd love but had no idea how long it would take (and there are many days I wish I'd just sold the place and moved). When I chose a career path there was no guarantee that it would make me money or make me happy. When I go out to my favorite brewpub I have no guarantee that I'll have a good experience that evening, and if I try a new restaurant for the first time I don't even have the benefit of past experience to refer to.
The point of all this is that life involves chances, it involves risks. It involves making the best decision you can with the information available. Sometimes life gives us the chance to make a change if new information comes to light. There's nothing stopping me from selling my house as it is, there's nothing stopping me from paying a contractor to fix it up to the point it's presentable and then selling it, there's nothing stopping me from pressing on and finishing the renovation the way I want it. If available information changes (cost of running it, noise from the road, family requirements, whatever) I can change the plan. If I started my career path and found I couldn't make any money, or I hated the work, or the hours were too long, I could have chosen a different path.
If what Scripture teaches us is true and that we have one life and then face judgment, finding out when it's too late isn't much help. Richard Dawkins can come up with whatever clever words he wants to present what he claims he'll do if he finds out he's been wrong his entire life but the reality is that he probably wouldn't get to do much of that. Likewise if it turns out the Hare Krishnas were right and we're condemned for spending our life following the wrong deity we don't get an Undo button. That said one benefit of ignoring the faiths that believe in reincarnation is that if they are right you at least get another life, and another, and another, until you figure it all out. If the orange-robed happy people are right maybe my next life will be as a cow or something. So the question of what I'd do if I find out I'm wrong when I stand before whatever deity I didn't expect to face is a moot point. If the atheists were right all along there's nobody to stand before and I'm worm food, in which case I hope I made some aspect of the world a better place while I was here.
Hence it goes back to forming the best decision you can with the available information. That doesn't look so much at what kind of life I have compared to what I might like to have but whether we can consider the claims by and about Jesus Christ to be credible. The standard of evidence we need is a personal decision.
It's not a perfect analogy, but some years ago I served on a jury. The case I heard was two young men charged with attempted murder. The prosecution laid out their claims detailing how the accused targeted the victim. The defense laid out their claims detailing how the accused did nothing of the sort and the real reason they were where they were (I'm being deliberately vague here because of rules about disclosure, and the precise details aren't relevant). We as the jury had to determine which one we believed. If we returned a guilty verdict two men were going to jail for a long time. If we returned a not guilty verdict those two men were going free. If we were wrong it meant either two innocent men lost a big chunk of their lives, or that two potential killers were turned loose on the streets. As the jury retired to deliberate not a single one of us knew for sure what happened - we weren't there. All we had to go on was witness statements, police statements and some aspects of evidence that neither side disputed. Those young men were probably in their early-mid 20s at the time and, unless something unexpected changed, are still in jail. Did we make the correct decision, or did we condemn two innocent men to over a decade in jail? I still can't say with 100% certainty, because I wasn't there. I can say that, based on the evidence, I am confident that those two men did what they were accused of doing - sufficiently confident that I sleep just fine at night knowing I was one of the jurors who returned that guilty verdict.
In the same way I can't produce conclusive proof one way or the other as to whether God exists, whether Allah/Ganesh/Krishna/Vishnu/FSM exists. All I can do is look at the evidence and keep looking until something satisfies me that it's worth following.