We have the Widsom text that asserts that Wisdom, which is often associated with the Spirit, was created???
We have the Pslam which at this point on Monday morning, I can't even begin to fathom preaching.
Canticle 2, Glory to You, which at least makes a reference to the Trinity as Father, Son, and Holy Spirit.
Romans 5.1-5 also mentions all three persons of the Trinity, but plays more on Pentecost themes than Trinitarian.
And Jesus trying to, but failing, make any sense of the relationship between the Godhead.
Good luck indeed.
What strikes me this morning, as it seems clear that one probably can't preach the day based on these texts, is that classic line from Romans 5, "we also boast in our sufferings, knowing that suffering produces endurance, and endurance produces character, and character produces hope, and hope does not disappoint us, because God's love has been poured into our hearts through the Holy Spirit that has been given to us."
Hope does not disappoint us. Amen? Amen.
This, I think, plays on the Creation theme that is present in the Pslam. God speaks things into reality, and so when he promises us something, it is already true. Our hope, set rightly on God's promise will not disappoint us because God speaks truth into being, because God loved us enough to send his Son, because God won't leave us alone, because the Spirit is active in our lives all the time. Our sufferings prove that it won't be easy, but our hearts, beating with the love of God, prove that our hope will not be in vain.
Maybe it is nice to not have to preach the Trinity on Trinity Sunday, nobody really gets that anyway. Why not preach hope instead; hope that does not disappoint.