~なければ (if not)

Without dreams, one cannot go on living.

However, regular dosing is absolutely essential, and even missing one day leads immediately to death.

My, my. No matter that it's just a phys-ed class... if you don't approach it with the determination of a real match, it won't be useful when the time comes for actual combat, you know.

Without taking risks, you get nothing.

If you don't study, there's no point in going to school.

It also teaches that for serious sins, you cannot receive forgiveness without confessing to a leader.

Without taking risks, you won't get anything.

Without taking risks, nothing gets started.

If you're not busy this weekend, would you like to go fishing together?