How do we know the doctrine of synecdoche is true?

The validity of synecdoche within the biblical context derives from consistent patterns seen across various scriptures. The overarching principle of this trope is evidenced through multiple passages where a part is utilized to denote the whole, or alternatively, where the whole represents a part. For example, in the Old Testament, the term 'all' is frequently applied to represent the majority or the most significant segment of a group, which is evident in Exodus 9:6 where 'all the cattle of Egypt died' pertains specifically to those in the field.

In the New Testament, similar examples are present. In Matthew 3:5, the text references 'all Jerusalem,' indicating the large number of people who responded to John's baptism rather than suggesting every inhabitant. This consistent utilization across diverse passages supports the doctrine's truth, helping readers grasp the deeper meaning and intent of the scripture as they engage with the text.