Here is the prayer for the Nativity from The Lutheran Liturgy, a book that accompanies The Lutheran Hymnal. I really like to use these prayers on the festive occasions.
CHRISTMAS + THE NATIVITY
O THOU GOD AND FATHER of our Lord Jesus Christ,
through whose grace we again celebrate the birth of our Savior,
we come into Thy presence with holy joy,
for Thou hast gloriously fulfilled Thy promises,
given to our first parents after the Fall, to the Patriarchs,
to Moses and the Prophets,
and to all Thy people of old,
who waited in hope for the Salvation of Israel.
Accept, we beseech Thee, our humble tribute of praise and thanksgiving,
and grant that through the birth of Thy Son
we may be born again in the spirit
unto the blessed hope of everlasting life.
O Jesus, Thou Son of God,
we bless Thee for becoming flesh of our flesh
and for enriching us with inestimable gifts from the treasures of Thy grace.
Thou hast made reconciliation for iniquity,
so that now we have peace with God and access to the Father.
Thou didst become the Son of Man,
that we might be made the children of God in Thee.
Bestow upon us a simple, childlike faith,
that in Thy lowliness we may adore Thee;
and give us grace to behold the glory shining through the veil of Thy humanity,
the glory of the Only-Begotten of the Father,
full of grace and truth.
Speak to us the words of life,
that, as Thou hast loved us, so we may also love Thee.
Be our Light in darkness,
our Abundance in want,
and our very present Help in trouble.
And as Thou didst descend from heaven to earth for our salvation,
so may we have power to ascend from earth to heaven,
to the glory of Thy great and adorable name.
O Holy Spirit,
we praise Thee for Thy comfort and guidance.
Incline our hearts to meditate devoutly on the sublime mystery of the Nativity,
and help us to embrace our Redeemer, in true faith, as our most precious possession.
Fill our hearts
with peace,
and comfort,
and hope,
and life,
and joy in Him.
Let us so keep the feast that at its close, with Thy benediction upon us,
we may resume the burdens of our several callings,
rejoicing in our salvation
and delighting to do Thy will.
O Holy Trinity,
who wouldst be praised for mercy rather than judgment,
we glorify Thee;
for Thou hast had respect unto the lowly.
Let Thy covenant of peace endure forevermore,
that we may rejoice in Thee,
world without end.
Amen.
