The friar responds by saying that some higher power has changed their original plans. This higher power is what people have no control over - fate. Through fate, the friar does not make it to Juliet's tomb on time. Romeo kills himself before the friar can tell him that Juliet is not really dead. This is not the friar's fault and it's accepted that he's not responsible for actions beyond his control. Rather, it is fate that he did not get there on time.
An important motif in Romeo and Juliet is nature. It is referenced several times throughout the course of the play. Nature is a representation of several aspects in Romeo and Juliet, including, their life, their death and their love.
Friar Lawrence is a nature-lover. He believes that plants are very similar to human beings. In Act 2 Scene 3, Friar Lawrence compares the cycle of nature to the cycle of life. .
The gray-eyed morn smiles on the frowning night,.
Checkering the eastern clouds with streaks of light,.
Now, ere the sun advance his burning eye,.
The day to cheer and night's dank dew to dry,.
I must upfill this osier cage of ours.
With baleful weeds and precious-juicèd flowers.
The earth, that's nature's mother, is her tomb.
What is her burying, grave that is her womb.
And from her womb children of divers kind.
We sucking on her natural bosom find,.
Many for many virtues excellent,.
None but for some and yet all different.
Oh, mickle is the powerful grace that lies.
In herbs, plants, stones, and their true qualities.
(II.III.5-17).
Here Friar Lawrence talks of his reverence and understanding of nature. In the beginning of this speech, Friar Lawrence mainly he talks about the smile that replaces the frown. The frown symbolizes Romeo's depression after Rosaline's rejection, and the smile that replaces it when Romeo meets Juliet. Friar Lawrence also observes that plants are born out of the Earth and they are buried in the Earth when they die. Which represents the cycle of a person's life.