Ro 8:14-17 - For all who are led by the Spirit of God are sons of God. 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, and if children, then heirs—heirs of God and fellow heirs with Christ, provided we suffer with him in order that we may also be glorified with him.
Slavery produces fear. Serving produces trust. When we don’t fear God, we will fear something else. Those who fear God receive a Spirit of Adoption that allows for an intimate relationship where instead of a cold, dead relationship, there is an intimate fatherly relationship. The Spirit bears witness that we are children of God, who have all the rights of being a son and a heir to all that is ours for inheritance. It is true that we will suffer, but it isn’t nothing to be afraid of, because we have the promise of a God who cares for us and a future inheritance awaiting us.
