De or het herkerstening?

The correct Dutch article is:

de herkerstening

Rule Words ending in -ing: almost always de. See the rule

How to use herkerstening

the herkersteningde herkerstening
this herkersteningdeze herkerstening
that herkersteningdie herkerstening
our herkersteningonze herkerstening
your herkersteningjouw herkerstening
every herkersteningelke herkerstening
which herkerstening?welke herkerstening?
a big herkerstening / the big herkersteningeen grote herkerstening, de grote herkerstening