What it means
ことにはならない expresses that a certain conclusion, result, or state does not automatically follow from the preceding information. It is often used to reject an overgeneralization, especially after a clause followed by からといって. The construction can refer to a future result or to a logical interpretation of an existing fact, depending on context. Its polite counterpart is ことにはなりません.
Usage note
Do not confuse ことにはならない with ことにならない. The latter commonly means that an arrangement or plan cannot be established or will not work out, whereas ことにはならない usually denies that the preceding information leads to a particular conclusion.
How to use it
努力したからといって、必ず成功することにはなりません。
Just because one made an effort, it does not mean that one will necessarily succeed.
努力したからといって、必ず成功することにはならない。
Just because one made an effort, it does not mean that one will necessarily succeed.