The poem is an expression of the anguish of a man following a spiritual and virtuous path to please the Almighty. It is accepted by every religion that the right path is the most difficult one. It is laden with thorns and difficulties. One following this eventually emerges triumphant.
It appears that the poet has been leading a virtuous life. He must have abstained himself from sensual pleasures, luxuries and materialistic joys.
The devotee speaker seems to have reached the edge of his endurance. He is losing patience and no more desires to undertake this journey of physical and mental pains. His patience is seemingly giving way to frustration and a sense of rebellion:
Have I no bays to crown it,
No flowers, no garlands gay? All blasted?
The 'bay' mentioned here refers to an evergreen shrub whose deep green leaves were earlier used to make crowns for those who triumphed in wars and battles.
The spiritual journey is no less than a battle between good and evil forces. To conquer the evil instincts and desires, one has to undergo great physical and mental penance.
The devotee speaker believes that in order to please God he’s been fighting the evil forces and undergoing indescribable pains. But there has been no recognition of his sacrifices. He has received no rewards or appreciation.
“Flowers” and “garlands” as crowns made of bay leaves stand for the spiritual rewards bestowed on them who follow the right path. He thinks he has been denied the rewards that he deserves.