Ibn Umar (Allah be pleased with them) reported Allah's Apostle ﷺ having said: When you are invited to a feast (even though it is) the leg of the sheep, you should accept it.
By accepting an invitation, we can show our gratitude towards those who have invited us as well as demonstrate our respect for them. Furthermore, this hadith also teaches us that it is better to accept an invitation than reject it out of pride or arrogance; this will help foster strong relationships between people which will benefit everyone in society as a whole.