As the ancient saying goes:
"There is no end to revenge".

The reason for revenge is a lack of understanding about the rule of "cause and effect" and that these resentments are kept in mind.

The result is that one will suffer throughout future lives.

In Buddhism,
it is said that all sentient beings are our former family members or relatives.

Everyone possesses the Buddha-nature and will become a Buddha in the future.

There is also a saying that goes
"One needs to establish good connections with others before he becomes a Buddha" .

Therefore, we should learn love and compassion from the Bodhisattva, and learn not to keep previous resentments in mind, and not to hate evil men.

Instead, we should solve these resentments,developing good connections with other people with an equal mind.