Xian ling (Chinese: 显灵) is the notion of a numinous, sacred (ling) presence of a god or gods in the Chinese traditional religion. The term can be variously translated as "divine efficacy", "divine virtue", or also "efficacious response"; these terms describe the manifestation and activity of the power of a god (灵气 ling qi, "divine energy" or "divine effervescence").
Within the context of traditional cosmology, the interaction of these energies constitutes the universe (the All-God, Tian), and their proper cultivation (bao ying) upholds the human world order.
The relationship between men and gods is one of reciprocal exchange of energy and the cultivation of godly energy. Through rituals of worship and proper conduct, people acquire and maintain a sense of stable world order, peace, and balance (bao ying). Violating the rule of reciprocity may undermine the balance and invite chaos.
The attitudes of the people towards their deities is one of awe and apprehension. Through devotional practices, a person strives to secure balance and protect himself and the world in which he is located from the power of unfavorable forces. In this sense, the traditional Chinese view of human life is not fatalistic, but is one in which one is the master of his own life through his relationship with the divine energies.
Within temples it is common to see banners bearing the phrase, "If the heart is sincere, god will reveal his power" (心诚则灵 xin cheng ze ling). This implies the belief that gods respond to the entreaties of the believer if his or her religious fervor is sincere (cheng xin 诚心). If a person sincerely believes in the gods' powers and accumulates the energy of piety, the gods are confident in his faith and reveal their efficacious powers. At the same time, for faith to strengthen in the devotee's heart, the deity must prove his or her efficacy.
Worship consists of the display of reverence or respect (jing shen 敬神) for the gods, honoring them through the fulfillment of vows (huan yuan 还愿). In most of the cases, vow-fulfillment is expressed in material form, for example jingxiang offering rituals. Many people repay vows to the gods by contributing incense, oil, candles, and money. Religious devotion may also be expressed in the form of performance troupes (huahui) involving stilt walkers, lion dancers, musicians, martial arts masters, yangge dancers, and story-tellers. Some gods are considered carnivorous, for example Heshen (河神), or the Longwang (龙王); offerings to these require an animal sacrifice (shengji 生祀), while other deities, for example Zhenwu, do not ask for animal sacrifice.