Love means if you love somebody, you must give something, you must accept something from them. You must disclose your mind and they should also disclose their mind to you. Then you make them eat (Offer a feast) and whatever eatable they offers you also accept.
These six kinds of exchange make love.
For example ,If you love somebody, then you exchange few gifts, food etc . You disclose your mind, “My dear such and such, I love you. This is my ambition.” etc .That develops love. These are the exchange of love.
But if you do not know the person how do you love? If you love somebody if you have not given anything to that (God) somebody, neither you have taken something from him, where is the love? .That means imperfect knowledge. The conclusion is religion means to love God, and to love means you must know who is God. There cannot be any other alternative. You must know the person who is God. Then you can exchange love.
Ref >> Srila Prabhupada Vani