This text comes from The Complete Poetical Works of John Greenleaf Whittier, a historical songbook transcribed on Wikisource and reproduced from the pinned revision linked below.
O dearest bloom the seasons know,
Flowers of the Resurrection, blow,
Our hope and faith restore;
And through the bitterness of death
And loss and sorrow, breathe a breath
Of life forevermore!
The thought of Love Immortal blends
With fond remembrances of friends;
In you, O sacred flowers,
By human love made doubly sweet,
The heavenly and the earthly meet,
The heart of Christ and ours!