The Shaykh (may Allah have mercy on him) said:

Second: Whoever places intermediaries between himself and Allah—calling upon them, seeking their intercession, and depending on them—has committed unbelief by unanimous consensus.

In truth, this is a form of shirk and, upon close examination, is subsumed under the first nullifier. Whoever calls upon the dead or the absent, seeks their help in times of ease or hardship, and relies on them for the fulfillment of his needs—whether for victory over enemies, forgiveness of sins, salvation from the Fire, healing of the sick, or relief from distress—claiming that he does so only to obtain their intercession, is following exactly what the idolaters used to do. Allah, exalted is He, says: “They worship besides Allah that which neither harms them nor benefits them, and they say, ‘These are our intercessors with Allah’” (10:18). He also says: “We worship them only so that they may bring us nearer to Allah” (39:3). Thus, they either worship the righteous themselves or the statues erected as symbols of them.

Whoever seeks closeness to such beings believing that they can benefit or harm, and that they direct the affairs of the universe and dispose of what is in it, has combined the two categories of shirk: shirk in rububiyyah (lordship) and shirk in uluhiyyah (divinity).

Shirk in lordship lies in believing that they manage the affairs of this world, that they possess the power to grant victory over enemies, forgive sins, save from the Fire, and to bring about—