There are many concepts about the relegion in reality cannot answered by the scientist or science, and within the amount of big intelligence also., except accepting a person sent by God as prophet like, jesus and moses, and mohammed peace be upon him. Therefore to understand the whole purpose of relegion can be explicitely described in the book of Quran and a translation is widely available to clear your doubt about the need of relegion etc. because subject required elaborate explaination and this QL chaptor, and space available is not convenient way of study of the topic in discussion.
Relegion is for love and forgiveness, is one of your definition and that is true, but you have only stated one atomic part of purpose in human life and his behaiviour towards to other people is just indicated. there are several area of study about relegion that makes a perfect faith and related deeds to make the life both successfull in this world and the world you are going to face after death which is exclusively explained in Quran as it was explained in previous vedic books etc. coz all of them are one God who created you and universe and everything in it with a purpose. Good luck.