How to convince Christan parents for love marriage? Both are Christan but cast different?

He is totally different from my fathers selection,so I don’t know what to say. one month before I came to know about this.i was worried somuch.he wont accept my partner.My parents hates intercast marriage & challenged about my marriage & told none of my childs love any one they are my blood. if they do like that then I will do suicide. this is my problem .what to do,I don’t want to hurt them in the same way I don’t want to miss my partner..Because of this I stayed far from him.think & tel me what to do.Actually he is so nice person for me,he is having very nice family & job,he loved me a lot,3 yars back I proposed my love to him.that time he didn’t accept my love.actually he didn’t belived love and all,after 2 years again I asked him that time he accepected my love.his parents also accepected to my marriage.really his parents are gud,Me SC Cast,His Cast BC.What to Do? I want both.