Today would be a good day to preach on God the Father, don't you think? It is Father's Day and Trinity Sunday. The Holy Spirit should have got some play last week for the Solemnity of Pentecost and Jesus has gotten play all year long, so today we should defintely hear something about God the Father.
In my dealings with people over spiritual matters, I've found that a lot of people have problems with God the Father. Of course it has more to do with earthly matters in the end than with God. Since I would remind all that when St. Philip asked Jesus to "show us the Father" that Jesus replied "anyone who has seen me has seen the Father." So in reality a good homily on the "Father" would be like a good homily on "Jesus." It would be kind of like most artists' rendition of the Trinity where God the Father is just an older version of Our Lord.
Today try to foster an ongoing sense of the adoration due to God the Father- thanking Him for all of creation with every breath that you take!