This phrase: "remain in my love" help me comprehend something of the mystery of unconditional love. Often I have been asked to explain how an infinite loving God of Mercy can also be a God of Justice, how a loving God can condemn to Hell. The phrase, "remain in my love" puts the emphasis on our own behaviour. God always respects our free will. We are not forced to do anything. Jesus loves us as the Father loves him. We have the choice. We can accept that love and remain in it. We can reject it. The choice is ours. God honours our choice in judgment. The Last Judgment will reflect our choices.
The test of remaining in the love of the Lord is keeping Jesus' commandments. "If you keep my commandments you will remain in my love, just as I have kept my Father's commandments and remain in his love."
The commandment of Jesus is to "love one another just as I have loved you." A simple illustration of how much the Lord has loved us is that he has laid down his life for his friends. a man can have no greater love than that!
Then there is the wonderful discussion on what is the nature of a friend. Jesus declares that fa friend is a person from whom you have no secrets. He or she knows the whole story. Jesus has made known to us everything that he has learned from the Father. There are no secrets. We are his friends.
The reading continues: "You did not choose me, no I chose you." Ask what you will and love one another.