Redemption:

1. When a person is sick, a redemption is the prerequisite of any cure. Only after the redemption has been made does the Torah give the doctor permission to cure (Likutey Moharan II, 3).
2. When a person fills the mouths of the Sages with wine, it is accounted to him like a redemption (I, 41).
3. Rising for the midnight prayer has the same power as a redemption (149).
4. It is a good practice always to give money for a redemption. This is the way to sweeten the power of harsh judgements at all times and be saved from them. Even when nobody in the house is sick and you have no particular problems, it is still good to present for a redemption in order to prevent any problems or sickness, God forbid (Chayey Moharan, Avodat Hashem 92).