Here’s a prayer for Trinity Sunday (the first Sunday after Pentecost). It was written by Thomas Turner and posted on Everyday Liturgy.
Prayer to the Blessed Trinity
God of the Heavens,
keeper of the stars,
Lord of the darkest, most remote places
of the universe,
the one who hovered and breathed life,
and the Creator of every living thing:
Be our salvation, our comfort,
our hope, for you are holy and righteous,
your words are true
and your light dispels all darkness.
Glory to the Almighty God,
Sun of Righteousness
and Breath of Life. Amen
~ written by Thomas Turner, and posted on everdayLiturgy. http://everydayliturgy.com/