The whole creation was altered by Thy Passion: for all things suffered with Thee, knowing, O Word, that Thou holdest all in unity.
He who at the beginning by His will alone set the earth upon its course, now descends dead beneath the earth. Tremble, O heaven, at this sight.
The spiritual powers and the angelic hosts are amazed, O Christ, at the mystery of Thy burial past utterance and speech.
~ From the Praises (commonly called the 'Lamentations'), Matins of Holy Saturday, celebrated on Holy Friday evening in anticipation. For more of these mystical and moving verses, see here.
On Great and Holy Saturday we also sing this hymn:
The great Moses mystically foreshadowed this day, when he said,
God blessed the seventh day.
This is the Blessed Sabbath;
this is the day of rest,
on which the Only-Begotten Son of God rested from all His works.
By suffering death to fulfill the plan of salvation,
He kept the Sabbath in the flesh;
by returning again to what He was,
He has granted us eternal life through His resurrection,
for He alone is good, and the Lover of man.
Holy Saturday can be "skipped over" so easily amidst the preparations for the Pascha/Easter Feast, but it is actually a profound mystical occurrence. See the article by Fr. Alexander Schmemann, 'This is the Blessed Sabbath'.
Is Jesus Christ calling you? Visit 'Journey to Orthodoxy', and visit an Orthodox Christian Church as soon as you can!