What is your advice for finding the theological significance of potential parallels within the Bible?

This text is from a letter written by David Gooding in 1999.

In that situation, where I do not myself at once perceive the theological significance of proposed parallels, what I would do first of all is to forget about apparent parallels and return to the detailed exposition of each of the stories, taken by itself. Only when we have seen the significance of all the details in any two stories, taken each one by itself, can we be in a sure position to see how the details in the one story may or may not be related to the details of the other story.

To apply this to your example of parallels between Ishmael and Isaac, take the story of God's attitude to Hagar and to her son in Genesis 16, and the attitude of the angel of God to Hagar and Ishmael in chapter 21. That surely is a parallel that one would have to understand and expound in detail before one compared either of these stories with the story of Abraham's sacrifice of Isaac in Genesis 22.

Yours very sincerely in Christ,