For what and whom is election a comfort?

Isn't it typical that when you decide to stop blogging you suddenly have some thoughts. Well, it is almost the end of May.

Here's a question which has germinated recently from a number of sources.

I believe in the doctrine of election, viz., that God has eternally decreed there will be a people populating the new heavens and the new earth, glorifying his Son, and that he has also decreed eternally (before the creation of the world in Ephesians' more temporal language) the individuals who will make up that elect people (contra Barth et al.), simply according to his sovereign mercy, not on the basis of any good works, foreseen faith etc.

I am accustomed to thinking that a function of this doctrine is to comfort me that God will keep me persevering to the end, so I will not fall away (and that the warnings of apostasy are one means he uses to keep me - thank you Prof. Schreiner). Indeed I think Calvin says something similar.

However, is that right (this function, not the doctrine itself - I know that's right)? Where in Scripture is election meant to comfort me personally that if I am big-E elect, I will not fall?

Is the comfort not rather that God's plan cannot fail, that His Church cannot fail, that his new heavens and new earth cannot fail, which is great news. Obviously, if I am big-E elect, that certainty will cause me to rejoice, regardless of whether I have the personal assurance that God will keep me.

Have I gone mad?

Update:
Thank you to those who've pointed out John 10 - a good place to start.