3 sentences

1. 他早已看破红尘，决定出家为僧。

   tā zǎo yǐ kàn​pò hóng​chén, jué​dìng chū​jiā wéi sēng.

   He has long since seen through the vanity of the world and decided to become a monk.

   Source: Dong Chinese Dictionary

2. 他决定遁入空门，从此不再过问红尘往事。

   tā jué​dìng dùn rù kōng​mén, cóng​cǐ bù zài guò​wèn hóng​chén wǎng​shì.

   He decided to enter the monastery and leave the secular world behind.

   Source: Dong Chinese Dictionary

3. 在这滚滚红尘中，很难保持一颗宁静的心。

   zài zhè gǔn​gǔn hóng​chén zhōng, hěn nán bǎo​chí yī kē níng​jìng de xīn.

   In this bustling mortal world, it is hard to maintain a peaceful heart.

   Source: Dong Chinese Dictionary