You are a blessing. Your very being in this world is a blessing that helps make the world more of what it is meant to be.
This is not true only sometimes, when you are at your best, or when you are living the "right" way. This is not only true when you are believing the right thing, or acting the way you're supposed to. It's especially not only true when you are being productive, useful, or competent. Your being a blessing is not based on something you are doing or have done. How can I say this with such confidence? Because the fact of your blessedness is about who God is and how God sees you.
God looks upon you with love. This is the Gospel. This is why church exists, why you and I even know each other - so that we can remember the basic reality that God is looking upon you, upon me, upon us, with love. To be looked upon with love is to be blessed. So our foundation, our genesis, the beginning of our self-understanding must be that we are in our very being blessed by God.