Kalika Purana has a beautiful extollation of Lord Shiva in the for of Shiva Linga. Worship of Lord Shiva in the form of Linga bestows tremendous blessings. Foremost among all the blessings is that it can confer tremendous peace. Shiva Linga is the closest conceptualisation of the form that bridges the manifest and the unmanifest. However this passage of kalika Purana provides insight into further nuances.

It is after demise of Sati Devi, Lord Shiva is subjected to unfathomable sorrow. Grief suspends Lord Shiva into a sense of denial, which gradually transforms into the rage that results in the decapitation of Daksha. Rage then transforms into incalculable grief. In this grief, he is roaming the worlds with Ma Sati's body on his shoulders. It is then Lord Vishnu, Lord Brahma summon Lord Shani (Saturn) , and with the help of Mahamaya, they manage to separate Ma Sati's body from Lord Shiva by cutting into pieces. This results in unmatta bhava in lord Shiva, almost intoxicated state resulting from sorrow. In this mood of unbearable grief, he turns into the form of Linga! This results in the arresting of all of the manifest universe. Because Shiva is verily the source of all existence. If he turns immutable, then all existence ceases to be. All Godly forces cease to be. All the Gods come together as Lord Brahma exhorts them to extoll Lord Shiva and pray to him to adorn his form that confers moment / spanda back to the manifestation.

This episode gives an opportunity for poignant reflection, that when one is drowned in grief, a deep depression, the vitality of all life is arrested. Thus by worshipping Shiva in the form of Linga, we seek his blessings to unfurl harmonious movement back to our existence. There can be juxtaposing reflection too, where agony and pain becomes unbearable, it becomes necessary to be absorbed in the state of Peace - hence we can observe that in the verses, Lord Shiva is repeatedly referred to as Shantha Murthy - embodiment of Peace - in the form of Linga.

Sharing below this beautiful verse from Kalika Purana

अनादिमध्यसंसरयोगविद्याय शमभावे।