启示 and 启事 have the same pronunciation but very different meanings. Check out the tips on how to differentiate between them.
启示 can be used either as a verb or a noun
启示 to reveal; to enlighten; enlightenment; revelation; illumination; lesson.
Examples:
这本书启示我们应该怎样度过一生。This book enlightens us as to how we should live. (启示 as a verb)
他后来告诉我说，他是读了你的专栏之后受到启示才给我打电话的。
tā hòu lái gào su wǒ shuō , tā shì dú le nǐ de zhuān lán zhī hòu shòu dào qǐ shì cái gěi wǒ dǎ diàn huà de 。He later told me that he had been inspired to call me after reading in your column.(启示 as a verb)
这些思想，对学报编辑实践乃至编辑学研究具有重要指导和启示作用。Zhè xiē sī xiǎng, duì xué bào biān jí shí jiàn nǎi zhì biān jí xué yán jiū jù yǒu zhòng yào zhǐ dǎo hé qǐ shì zuò yòng. Those ideas will offer important instructions and inspirations for the practice of journaleditors and the study of editing. (启示 as a noun)
启事 can only be used as a noun.
启事 notice; announcement; advertisement
Examples:
他们还在刊登订婚启事啊。 tā men hái zài kān dēng dìng hūn qǐ shì 。They still print engagement announcements. (启事 as a noun)
这个启事已经刊登在报纸。zhè ge qǐ shì yǐ jīng kān dēng zài bào zhǐ 。This notice has been advertised in the newspaper. (启事 as a noun)
她张贴了一则寻狗启事。tā zhāng tiē le yì zé xún gǒu qǐ shì 。He posted a notice about her lost dog. (启事 as a noun)
今天早晨看见报上订婚启事，我才知道。Jīntiān zǎochén kànjiàn bào shàng dìnghūn qǐshì, wǒ cái zhīdào. I just learned about it this morning when I read her engagement announcement in the newspaper. (启事 as a noun)