There are very few relationships where the giving is only one sided. Every person who is in your life gets something out of being part of you. None of them exist only to give to you; not your best friend, not your teachers, not even your parents. That is why Jesus is like no other person in your life.
No matter how you look at it, Jesus received nothing from giving himself for you. He came entirely for your benefit. Jesus came so that you can have full life through him:
I am the gate. Whoever enters through me will be saved. They will come in and go out and find pasture. The thief enters only to steal, kill, and destroy. I came so that they could have life—indeed, so that they could live life to the fullest. (John 10:9-10)
God doesn't need us. He is self contained within the God-head. He does not need the angels. He does not need creation. He does not need mankind. But he created us and made a covenant with us, and even though we broke relationship with him, he never gave up on us. He gave himself entirely so that we could have life to the fullest, as he always intended for us to have, simply because of his word to us.
We certainly didn't merit Jesus' death. We do not merit his love. No matter what we do we could never earn it; never. But he freely gave it at no cost to us and to no benefit for himself. He paid the full cost only for our benefit. No one else could ever show that kind of love for us.
And all we have to do is accept it.
Everything that needs to change in us will be changed by the power of the love we accept into our selves. We don't receive it after we have changed. We change after we accept it because that love transforms us, making us a new creation, and continues to transform us until we are just like Jesus. Again, all for our benefit.
Don't ever think that God did this because he needs something from us. Don't think that he needs our worship, our talents, our offerings. He needs nothing. He did this because of the purest form of love; a love that is God himself. For this we gladly give him our lives, because such love provokes absolute trust, service of gratitude and whole-hearted worship. So take time to come to as deep an understanding of this love as God is willing to reveal to you.