Who is a child?
In the Bible, the story of the prodigal son tells us that the son went to his father and asked for his inheritance. I think the father never denied her, but allowed her to leave. This means that the prodigal son left with the father's consent, but not with his blessing.
When the prodigal son returned to his father, he begged him to accept him as a servant. He didn't come demanding. He came with a correct attitude of repentance, which made his father welcome him with open arms.
How do we know that we are children?
We are a treasure; a treasure acquired in a special way. We were not redeemed by something corruptible, such as gold or silver, but we were redeemed by the blood of Jesus.
You do not earn the right to be a child. By grace and adoption we are children, just as Jesus is by nature.
We have received an invitation from God. He wants us to continually draw closer to Him, because we are His children.
“Then God said: Let us make man in our image, according to our likeness; and rule over the fish in the sea, over the birds of the sky, over the beasts, over all the earth, and over every animal that creeps on the earth. -Genesis 1:26
What do we inherit?
The book of Ephesians says that we are seated in heavenly places together with Christ. We are blessed with every spiritual blessing.
"All things" includes everything and nothing is excluded.
God wants us to be strengthened. God strengthens and empowers us.
"Behold, I give you the power to trample snakes and scorpions, and over all the enemy's strength, and nothing will harm you." -Luke 10:19