Rashi says that: וַיִ קְ רָ א “Vayikra” is a “Lashon Chiba” (style of affection). Why by Korbanos do we have affection? Korban means being close (Karov) to Hashem. What makes a person close by bringing a Korban? We can suggest that by seeing the inner workings of an animal, a person sees the marvelous human machine, and the miracles of his daily functions. We need to be thankful for our internal functions which we don’t see.
Be grateful that your: רִ בָ אֵ ים body parts are faithful to you for a lifetime; this is basic gratitude for your very existence. When you Shecht an animal as a substitute for what could happen to you, then you appreciate your life as if you just had Hatzalas Nefashos. When Raichav and Ba’ana told Dovid that they assassinated his adversary, Ish Boshes, Dovid swore that he would kill them, since Ish Boshes was innocent.
Dovid swore by saying: חַ י ה' א שֶ ר פָ דָ ה אֶ ת נַפְ שִ י מִ כָל צָ רָ ה ש"ב ד ט I swear in the name of Hashem, who has saved me from every distress. This story happened right after Dovid became Melech. At the end of his life, Bas Sheva complained that Adoniyahu was attempting to become Melech, even though Dovid had already given her his promise that her son Shlomo would become Melech. He called her and swore to her, that that very day he would keep his word, and have Shlomo sit on his throne.
He swore with exact same words he used at the beginning of his Malchus, and he said: חַ י ה' א שֶ ר פָ דָ ה אֶ ת נַפְ שִ י מִ כָל צָ רָ ה מ"א א כט I swear in the name of Hashem, who has saved me from every distress. Notice how he uses the exact same Lashon consistently. We see from here an obvious lesson. A person should develop a close connection with Hashem, by always being thankful to Hashem for saving him from Tzaros!
Now we know why having Tzaros and pecklach is so much part of every person’s life; as soon as he is saved, he will forever be thankful to Hashem. For good reason we are always thanking for Yetzias Mitzrayim. And a Korban is the same idea; it brings you close to Hashem when you realize that Hashem allows an animal to be killed instead of a person (Ramban) similar to the idea we say in Kaparos: זֶה ח לִ יפָ תִ י this is instead of me.
