The Midnight Prayer of Mourning for the Temple-- Tikkun Chatzot:

1. How precious it is to rise at midnight in order to pray and meditate and study Torah. Try to make it a regular practice. Then you will be worthy of succeeding in the task of separating the good from the evil in the world. You will also develop a good memory which means always to remember your purpose in life and to keep in mind the enduring life you are destined for in the end. You must recognize that everything you do in this world only has meaning in relation to the World to Come. You should reflect on every experience which God sends you: consider all the different situations you find yourself in each day. The only purpose of all of them is to offer you hints as to how you can draw closer to God at every moment. This is the only true and enduring goal in the world. The entire purpose of man's being sent into this world is only to come closer to God. All the days of his vanity, all the experiences he has on each one of them are only for this (Likutey Moharan I, 54).
2. Rising at midnight sweetens the harsh judgements. This practice is as valuable as presenting a redemption (149).
3. Throughout the year, the correct time for the midnight prayer is when the first six hours of the night have passed. It lasts for two hours until the end of the second `watch.' In the morning, it is a good thing to look up at the sky. This will give you Da'at, knowledge of God.
4. The exile has already lasted so long. God is only waiting for the moment to return to us and rebuild the Holy Temple. It could happen at any time. Our task is to see that from our side we do nothing to obstruct the rebuilding of the Temple. On the contrary, we must make every effort to hasten it. This is why we should be so careful to get up each night at midnight and mourn for the destruction of the Holy Temple. Perhaps in a previous incarnation we ourselves were responsible for something which brought about the destruction of the Temple. Even if not, it could still be that our sins in our present lifetime are holding up the rebuilding of the Temple, and this is as bad as if we had actually destroyed it. This is the reason why we must weep and mourn every night at midnight. When we do so, it is as if we were actually making a tremendous effort to rebuild the Holy Temple. Then we will be able to draw closer to truth to the true Tzaddikim and those who are genuinely God-fearing. They are in fact the embodiment of truth, in its beauty, splendor and pleasantness. Through drawing closer to them your eyes will be opened and you will be able to see how far your own development has advanced and in which areas you need to work in order to return to God and to know and acknowledge His great and holy Name (Likutey Moharan II, 67).
5. The merit of rising for the midnight prayer protects us from destruction by fire (Ibid.).
6. The main devotion of the Jew is to get up every night in the winter for the midnight prayer. In the summer, when the nights are short and we do not rise for the midnight prayer except in the Land of Israel, he should be sure to get up with the dawn each morning (Rabbi Nachman's Wisdom 301).