It was said that in his youth, Lu Jingchu was both capable and modest, and after he passed the imperial examinations, was made an officer at Yang Prefecture (揚州, roughly modern Yangzhou, Jiangsu).
At that time, both Ji Xu and his father Lu Yuanfang were deputy ministers of civil service affairs in charge of selecting officials.
In 711, Emperor Ruizong's powerful sister Princess Taiping was set to recommend her lover, the official Cui Shi, as chancellor.
Thereafter, Lu was given the designation Tong Zhongshu Menxia Pingzhangshi (同中書門下平章事), making him a chancellor de facto, and was also put in charge of editing imperial histories.
Initially, Lu was set to be executed as well, but Emperor Xuanzong, knowing that he was not actually a member of Princess Taiping's faction, commented to him, "Only in the cold can one tell that the pine and the cypress are evergreens."
He further created Lu the Duke of Yan, gave him the honorific title Yinqing Guanglu Daifu (銀青光祿大夫), and initially had him remain as a chancellor.
When Emperor Ruizong heard of the incident, he climbed up the tower at Chengtian Gate (承天門) to try to figure out what was happening, and stated to the officials who gathered, "If you will help me, stay.
Hurting others to benefit myself is not the way of kindness and forgiveness.At a later point, Lu was made the mayor of Hezhong Municipality (河中, roughly modern Yuncheng, Shanxi).
(The first two sentences of this quote was eventually simplified and turned into the idiom tianxia ben wushi, yongren zi raozhi (天下本無事, 庸人自擾之).)
In 722, he was put in charge of selecting officials at the ministry of civil service affairs, and was further made the minister of justice (刑部尚書, Xingbu Shangshu).
In 725, he returned to public service, to serve as the prefect of Tong Prefecture (同州, roughly modern Weinan, Shaanxi), and was soon made an advisor to the crown prince.