I found this in 'Hymns Ancient and Modern', and am particularly fond of the second and third verses. Wikipedia has an exceptionally (rather bizarrely) detailed article on the author, Bishop Mandell Creighton, out of which mass of information I chiefly, sentimentally glean that he first spoke to his future wife at a Valentine's Day luncheon in Brasenose College, Oxford. That was in 1871 and he didn't write this hymn until 1900, but perhaps we can claim the germ of it for Brasenose.
O Thou Who gavest power to love
That we might fix our hearts on Thee,
Preparing us for joys above
By that which here on earth we see:
Thy Spirit trains our souls to know
The growing purpose of Thy will,
And gives to love the power to show
That purpose growing larger still;
Larger, as love to reverent eyes
Makes manifest another soul,
And shows to life a richer prize,
A clearer course, a nobler goal.
Lord, grant Thy servants who implore
Thy blessing on the hearts they blend,
That from that union evermore
New joys may blossom to the end.
Make what is best in each combine
To purge all earthly dross away,
To strengthen, purify, refine,
To beautify each coming day.
So may they hand in hand advance
Along life’s path from troubles free;
Brave to meet adverse circumstance
Because their love points up to Thee.