One part of the Pesach seder that has always bothered me is saying that if God had not taken us out of Mitzrayim at that time we would still be slaves today. This seems lacking in faith in God; surely if not then, He would have had His reasons and would have redeemed us at a later time. Why do we hold that that single point in time was our only opportunity for redemption from slavery?
Edit: as pointed out in one of the answers, this translation of "mesheubad" was flawed, though the broader point about this being pretty much our last chance for redemption still holds (as discussed in some of the answers).