Who question you on how you base your beliefs on faith and not actual facts? Cause I'm having that problem in another topic and I feel like I'm not a strong Christian when they tell me that I'm basing my faith on a bunch of lies and I can go to the library and find out they're right and my faith feels so weak. I love Jesus and I want to have strong faith in Him,.. but it's making me question and doubt myself of the possibility that they might be right and I'm scared of losing my salvation again.
Typically, atheists claim they seek truth, facts and evidence. In some cases, that might even be true.
But more often, they look for information that will reinforce their existing viewpoint. And to be charitable to them, we Christians are often guilty of the same thing.
I find Pascal's Wager to be pretty reductive in most cases. Still, the fact remains that Pascal's Wager is broadly true. Belief in God costs me nothing. Disbelief in God could cost me everything. There's really no percentage in disbelief.
An atheist with above average intelligence will usually respond that Pascal's Wager is predicated upon fear. And while there's an element of truth to that (i.e., the Christian's fear of Hell and damnation as the price for disbelief), the logical counter-argument is that rejecting the principle of Pascal's Wager is also motivated by fear (i.e., the atheist's fear of admitting to error).
As a general statement, our relationship with God is based on faith. However, we remain in a sinful state. Our faith is therefore imperfect. How can we live in a state and being of sin while possessing a perfect faith? That would be a logical paradox. But the entire point of grace is God making up for our shortcomings. You say you have a weak faith.
Of course you have a weak faith. Frankly, I'd have to call you a liar if you had said your faith was invincible.
In the end, atheists discussing these matters with theists is always an evangelistic exercise. You're evangelizing your religion but don't forget that they're evangelizing their religion too. You admit to being weak in your faith. Trust me, the average atheist possesses a faith so weak that your faith looks like a glimmering castle by comparison.
Keep at it!
EDIT- For clarity's sake, all of the above assumes a debate between theist and atheist based on philosophy. Very often, atheists want to switch the subject over to popular understandings of science. But that's foreign territory for most people and I advise against scientific debates (A) since both sides are probably unqualified to argue anything and (B) our faith is not based on scientific realities. Philosophy, however, is far more persuasive for most people and it's a subject that (in theory) anybody can grasp if it's explained properly and if their minds are open. So stick with philosophical argumentation, I say.