Faith is involved, but Pascal is also pointing out that it’s actually more REASONABLE to believe in God.
It’s not just faith, it’s understanding the reality of what it means to believe. If you don’t believe you don’t believe, period. Faking it “just in case” isn’t believing, the REASONABLE then is to be who you are. If you don’t believe and you’re wrong (ie there is God) faking it ain’t getting you into heaven because He knows you don’t actually believe. The Wager also runs into problems in that it’s binary in a very NOT binary world, one doesn’t simply believe in God, you gotta pick a brand, and often sub-brand, and flavor, there’s lots of religions out there many with splinter groups. Presumably they don’t ALL get it right (if only because they all think the others are wrong so it’s not logically possible for them to all be right), at least some of them aren’t going to heaven, and if you pick wrong you might as well have not believed for all the good it did you.