Why might the cell theory actually be a law?

Due to a law being a predicted sort of event that is bound to happen every time, a pattern, we can say that since the cell theory is a pattern instead of a possible explanation, it can be a law. However, since we don't have an accurate explanation to the part which claims that they all come from pre-existing cells, it is a theory, we don't have enough information to confirm that the theory is a solid fact, therefore, we can't confirm that it is a law.