Explanation:
“Fallen cherub, to be weak is miserable,
Doing or suffering: but of this be sure,
To do aught good never will be our task,
But ever to do ill our sole delights

As being the contrary to his high will 

Whom we resist.”
(Lines 157-162)

Answer: These lines have been taken from ‘Paradise Lost’ Book I, the great epic, composed by John Milton, the most distinguished poet of England in the seventeenth century. In these lines, Satan furiously lashes at Beelzebub for what he considers to be his (Beelzebub’s) weakness or cowardice.

Beelzebub’s pessimistic reaction to Satan’s first speech invites rebuke. Satan feels that Beelzebub is betraying signs of weakness by regretting the terrible war and their consequent overthrow from Heaven to Hell. In these lines, Satan tells Beelzebub to shun weakness, because it begets misery. Implicitly Satan concedes that physically they are weaker than God and this itself can be the cause of their miserable state whether they are active or passive. But they have an indomitable will never to do good. Satan explains to them the form of their revenge. They should not engage themselves in open hostilities and they have decided not to do any good but would find delight in doing evil because this act of doing evil is against His will. If His plan is to produce good from the evil that has been done by them, they should in their turn do their best to prevent its success.

Satan hopes that they might succeed in their endeavour to cause annoyance to Him and also they would be able to frustrate the most cherished plans of God from being fulfilled according to His expectations and wishes.

As a leader of fallen angels, Satan’s concept of weakness and strength may seem convincing but ethically it is untenable.