Unfortunately, "a blessing" is not something you can "learn to be". A blessing, in this sense, is a great help and/or comfort [to/for someone.]
You either are a blessing to someone, or you are not. And the other difficulty is that you must be a blessing
to someone.
This washing machine is a blessing [to me]! Before I had it, I spent hours washing clothes. Now it is done automatically!
I mean from be a blessing is like this story
"Deborah Falcao has a longing to use her life to serve God. In this way she can be a blessing to those that she comes into contact with in her life.Deborah Falcao has a longing to use her life to serve God. In this way she can be a blessing to those that she comes into contact with in her life"
That is a bad example of a "blessing": it is hard to see, if she only serves God, how she is a great help and/or comfort [to/for someone.] If she wants to be a
"blessing to those that she comes into contact with in her life", she really needs to help people in a real way.
"I am not well and my daughter lives 20Km away, but every morning she comes and makes me a meal and then, in the evening she returns with all of my shopping. She is a real blessing [to me]!"
In this way, .........she can be.. [a blessing {to those that she comes into contact with in her life}.]
Adverbial phrase...S....verb.....[...noun...]..{.........................adjectival phrase.......................}.]
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