What am I supposed to get from John 1:12?
I really don’t know. What am I supposed to get from reading and studying the Bible? For instance: "But as many as received Him, to them He gave the right to become children of God, even to those who believe in His name." What should this mean to me?
To understand what a passage means to you, you first need to understand what it was saying to its immediate audience. In the introduction to John, John is explaining the relationship of the Creator to His creation.
"He was in the world, and the world was made through Him, and the world did not know Him. He came to His own, and those who were His own did not receive Him. But as many as received Him, to them He gave the right to become children of God, even to those who believe in His name, who were born, not of blood nor of the will of the flesh nor of the will of man, but of God" (John 1:10-13).
Men were made in the image of God by God Himself (Genesis 1:28). Yet, when the Creator entered His own creation, the people he made did not recognize Him for who He is. He even came to the Israelites -- the people that God chose out of all the nations to be His special people (Deuteronomy 10:15) -- and they rejected Him.
However, that rejection was not universal. Those few who did accept Jesus as their Lord and God, He gave them the right to become God's children. "So also we, while we were children, were held in bondage under the elemental things of the world. But when the fullness of the time came, God sent forth His Son, born of a woman, born under the Law, so that He might redeem those who were under the Law, that we might receive the adoption as sons" (Galatians 4:3-5). Those who have accepted Jesus believe in His authority over their lives (that is what "in His name" means). These people are not born followers of Christ as the Israelites were born Israelites. They cannot become children of God by following the desires of the flesh (John 3:6). Nor do they become Christians because they do what some other men say they must do. It is God who chooses His children.
What does this mean for you? That you too have a right to become a child of God but it requires that you accept the authority of Jesus over your life. "Why do you call Me, 'Lord, Lord,' and do not do what I say?" (Luke 6:46). It requires trusting Jesus. We are children of the one we follow. You cannot be a child of God by following worldly passions or the teachings of men. "As obedient children, do not be conformed to the former lusts which were yours in your ignorance, but like the Holy One who called you, be holy yourselves also in all your behavior; because it is written, 'You shall be holy, for I am holy'" (I Peter 1:14-16).