en_tn/eph/03/03.md

according to the revelation made known to me

"that God a revelation known to me" or "that God reveled to me"

the hidden truth about which I wrote a little previously

"the previously not known truth that I briefly wrote to you about before".

When you read about this

"this" refers to the hidden truths that Paul is making known to the Ephesians.

you will be able to understand

"you will be able to comprehend" or "you will be able to realize".

my insight into this hidden truth about Christ

"my understanding into this previously not known truth"

which in other generations was not made known to the human race

"which was not made known to people in the past"

but now which has been revealed

"but now it has been shown" or “but now it has been made known”