Islam makes certain times and places especially sacred. While a believer can certainly engage in worship such as remembering or glorifying God at any time (“standing, sitting or lying on their sides”[1]), some periods of time have special and unique blessings associated with them. Similarly, while the entirety of the Earth has been made a place of worship and prostration, there are some locations (such as the three Mosques) that are uniquely blessed. This creates within the psychology of the believer a yearning to seek out these unique opportunities in order to come closer to Allah. That yearning brings about several positive spiritual emotions: awe, reverence, wonder, anticipation, eagerness, excitement, hope, and longing, all of which are encompassed in the term shawq.[2]
As we live today in an era of digital distractions and materialistic heedlessness, often acts of worship are squeezed into brief moments in our daily routine, which does not furnish one with a complete transformative spiritual experience. Serious worship requires not just taking a brief moment to pray, but allowing our prayers to define our direction in life. Thus, Islam offers opportunities for intense spiritual experiences, experiences that involve setting aside the dunya (worldly life) and its distractions. Of the greatest of such opportunities are the blessed nights of Ramadan. The Prophet Muhammad ﷺ said, “Whoever spends the nights of Ramadan in prayer out of faith and in the hope of reward, he will be forgiven his previous sins.”[3] The foremost of these opportunities are the last ten nights of Ramadan. As the Prophet’s wife `A’isha narrates, “When the last ten nights began Allah's Messenger (peace be upon him) kept awake at night (for prayer and devotion), wakened his family, and prepared himself to observe salah (with more vigor).”[4] It is no coincidence that i`tikaf (seclusion in the masjid) is also recommended in Ramadan. The Prophet Muhammad ﷺ used to practice i`tikaf for the entirety of the last ten days of Ramadan.[5] 
By far however, there is no day or night that has been emphasized more than the night known as laylat al-qadr (the Night of Decree). The Qur’an’s 97th chapter is dedicated entirely to this night:

Indeed, We revealed [the Qur'an] during the Night of Decree. And what can make you know what is the Night of Decree? The Night of Decree is better than a thousand months. The angels and the Spirit descend therein by permission of their Lord for every matter. Peace it is until the emergence of dawn. (97:1-5)

The companion Anas ibn Malik reported: “Ramadan approached, so the Messenger of God said: ‘This month has come to you, and in it there is a night that is better than a thousand months. Whoever is deprived of it is deprived of all goodness, and no one is deprived of its goodness except one who is truly deprived.’”[6]
The precise night on which Laylatul-Qadr occurs has not been mentioned. The Prophet Muhammad ﷺ said, “Search for Laylatul-Qadr in the odd nights of the last ten nights of Ramadan.”[7] There is a tremendous wisdom behind not knowing exactly when it occurs, which scholars have pointed out. As Ibn Qudamah al-Maqdisi (d. 620 H) writes:

God has concealed this night from the ummah so that they may strive in seeking it and performing worship throughout the month in the hopes of catching it. Similarly, He concealed the hour of special acceptance on Friday so that one would increase in their supplications throughout the day, and He concealed His Greatest Name (ism al-a’dham) amongst His Divine Names and His Pleasure with acts of obedience so that people would strive for them. And He concealed an individual’s lifespan and the Hour [of the Day of Judgment] so that humanity would continuously strive in good deeds, being heedful of them.[8]

The theological significance of Laylatul-Qadr 

What is the connection between its function and its virtue?

Seeking its rewards