Why not speak of Christ?

Wherefore, be reconciled
unto him through
the atonement of Christ,
his Only Begotten Son,
and ye may obtain
a resurrection,
according to the power
of the resurrection
which is in Christ,
and be presented
as the first-fruits
of Christ
unto God,
having faith,
and obtained
a good hope
of glory in him.

And now, beloved,
marvel not
that I tell you
these things;
for why not speak of
the atonement of Christ,
and attain to
a perfect knowledge
of him?