This seems like a troll thread, one that potentially violates the webdip forum terms, as jmo pointed out above. That said, I'll respect the question and questioner by assuming it was meant in good faith, rather than intending to degrade or disrespect anyone.
Short answer is: the question seems to indicate a misunderstanding or ignorance of religious customs.
Long answer: I will guess that the question refers to the Christian religion specifically, rather than "religion" in general. The period of time it refers to could be the Christian season of Lent (5-6 weeks before Easter, not 40 days), where traditional Christians remember the events which led up to the crucifixion and resurrection of Jesus. This includes suffering, but is by no means limited to it--the scriptural accounts are overflowing with literary and historical insights (and spiritual value, if you're a believer). However, that traditional churches chose to emphasize these events.... might be mistaken for "celebrating the brutal slaughter of God," if you're looking at it from the outside. Under the assumption that the question is intended to seek knowledge (rather than trolling), I invite further and more specific questions about why Christians do set aside time to remember and re-read these narratives.
Regarding the notion about charitable giving, it already happens during Lent. Besides being a remembrance of what Christ has done for fallen and broken humanity, the season of Lent is a time of repentance and reflection on our own shortcomings. Many well meaning people earnestly use this time to improve their own attitudes and treatment of others. Charitable giving is a part of this, though religious people in general tend to give year-round. At my church, for example, we took up a special offering during Lent to help inner-city families in crisis situations, but year-round we run a large food pantry to distribute food to the poor. source: I'm a Christian, in a conservative Lutheran church body.
That said, the question seems like a troll, and I salute you for a well crafted troll question (topic is important to lots of people, just enough vagueness to be misleading, but just enough specific complaint to get people going, etc).