unless (you do something)
Verb ない form + ことには
This grammar point is used to express that a certain condition is absolutely necessary for a following result to occur. It translates to 'unless' or 'if not'. The second part of the sentence is almost always a negative statement, indicating that something cannot be done or will not happen without the first action.
Verb ない form
The verb is placed in the negative informal form (ない form) followed by ことには. This sets up the 'unless' condition.
見
Unless I see it, I cannot believe it.
やってみ
Unless you try it, you won't understand.
雨がやま
Unless the rain stops, we cannot go out.
The clause following