From Aquinas’ Commentary on Romans regarding verse 2:10.
204. Second, he shows this in regard to the good: first, he repeats the two things mentioned above, namely, glory and honor, but the third, namely, peace, he mentions instead of immortality, which includes peace among many other things.
For a man’s peace cannot be complete as long as he fears he might lose the good things he has; rather, one has true peace of heart when he has everything he desires and no fear of losing them: my people will abide in a peaceful habitation (Isa 32:18).
I read this earlier this week and it has stuck with me. It made me realize that true peace can only be found in the love of God. This can never be taken from you. Everything else is changeable and it can fail us or we can lose those good things we have. God is unchangeable and in whom we can place all our trust without disappointment. At least if we truly trust even when we cannot understand.
Realizing this is one thing. Living it is another.