and I was advancing in Judaism above many equals in age in mine own race, being more abundantly zealous of my fathers' deliverances,

I went in response to a revelation, and in a private meeting with the reputed leaders, I explained to them the gospel that I'm proclaiming to the gentiles. I did this because I was afraid that I was running or had run my life's race for nothing.

For we Jews by race and not sinners of the gentiles,

This story may be taken as an allegory. The women stand for two Covenants. One Covenant, given from Mount Sinai, produces a race of slaves and is represented by Hagar

You were running [the race] well; who has interfered and prevented you from obeying the truth?

A little yeast makes the whole batch of dough rise!