The Holy Spirit confirms your adoption into God's family through faith in Jesus Christ, that you may know Him as your Father. Jesus taught us to address God as our Father in prayer. Through faith in Christ, the Holy Spirit brings you to know God as your Father. You come to God as your Father in Christ by the Holy Spirit.
"For you did not receive the spirit of slavery to fall back into fear, but you have received the Spirit of adoption as sons, by whom we cry, 'Abba! Father!' The Spirit himself bears witness with our spirit that we are children of God" (Romans 8:15-16, ESV).
In New Testament days, the Roman law for adoption illustrated how you are adopted into God's family to know Him as your Father. In those days, if an older man did not have a son, he could adopt one according to the law. First, he must choose the son. Second, he must pay a price to adopt a son. Third, there must be witnesses present at the official adoption ceremony.
The illustration makes it clear how you are adopted to know God as your Father. God chose you in Christ (Ephesians 1:4-6). He paid the price through His only begotten Son at the cross. Jesus paid it all for you to be God's adopted child. The Holy Spirit is the witness that you are adopted as God's child by faith in our Lord Jesus Christ.
