The purpose of giving gifts is to show how much someone means to us and to celebrate the person the gift is in honor of.
It can also be aimed at amending our past bitterness and misunderstandings in order to refresh our relationship.

I couldn't understand some parts of those sentences above " to celebrate the person the gift is in honor of" what does it mean? Is there any other ways to say things like this?
Also, is there any other way to say amending out past biterness and misunderstandings in order to refresh out relationship?
Thanks!

Question

The purpose of giving gifts is to show how much someone means to us and to celebrate the person the gift is in honor of.
It can also be aimed at amending our past bitterness and misunderstandings in order to refresh our relationship.

I couldn't understand some parts of those sentences above " to celebrate the person the gift is in honor of" what does it mean? Is there any other ways to say things like this? 
Also, is there any other way to say amending out past biterness and misunderstandings in order to refresh out relationship? 
Thanks!

Answer

Good questions!

We could simply say "The purpose of giving gifts is to show how much someone means to us and to celebrate them/that person/the recipient". Much easier and straightforward English!

You're right to question the next sentence!  We'd rarely use 'amending'.

How about.."It can also be for removing our past bitterness and misunderstandings to re-kindle relationships"

Nie przegap okazji, by nauczyć się języka w zaciszu własnego domu. Przejrzyj naszą ofertę doświadczonych korepetytorów i zapisz się na pierwszą lekcję już teraz!