Which lines in this excerpt from act v of shakespeare's romeo and juliet reflect the conflict of person versus the unknown?

(juliet wakes)
juliet: o comfortable friar! where is my lord?
i do remember well where i should be,
and there i am. where is my romeo?

friar laurence: i hear some noise. lady, come from that nest
of death, contagion, and unnatural sleep:
a greater power than we can contradict
hath thwarted our intents. come, come away.
thy husband in thy bosom there lies dead;
and paris too. come, i'll dispose of thee
among a sisterhood of holy nuns:
stay not to question, for the watch is coming;
come, go, good juliet,
(noise again)
i dare no longer stay.

juliet: go, get thee hence, for i will not away.

(exit friar laurence)

what's here? a cup, closed in my true love's hand?
poison, i see, hath been his timeless end:
o churl! drunk all, and left no friendly drop
to me after? i will kiss thy lips;
haply some poison yet doth hang on them,
to make die with a restorative.

(kisses him)

thy lips are warm.

The lines in the above excerpt from Act V of Shakespeare's “Romeo and Juliet” which reflect the conflict of person versus the unknown are:

“Of death, contagion, and unnatural sleep:

A greater power than we can contradict 

Hath thwarted our intents.”

When Juliet rises from her 'unnatural sleep' and asks Friar Laurence about her beloved Romeo she comes to know that Romeo had died after drinking the poison. Frair Laurence tells her that 'a greater power' which is death has shown its supremacy and had occurred.

The stretch that reflects the conflict of the person versus the unknown is  "Of death, contagion, and unnatural sleep:

A greater power than we can contradict  

Hath thwarted our intents."

In this passage Frei Laurence is explaining to Juliet that "a greater power" took the life of Romeo and that they can do nothing about it, because this greater power is more powerful than them.

And this is a perfect example of conflict between a person and the unknown, because until then the "greater power" which the friar was referring to was something unknown to them who are people.