Just to add a few words to the excellent replies you’ve already received, Catherine, I discovered that in Ro 8, at least in my translation, when the word is Teknon, it’s translated “children,” but when the word is Huios, it’s translated “sons.” This isn’t a gender thing, though – at least not for us.
A teknon was a child, male or female, who had not reached majority, and was not considered mature or ready to represent the family as an adult member. The higher classes would have a trusted servant (tutor) train the child in the family business, family affairs, ethos, etc., to be an accurate representative of the patriarch of the family. In this sense, a native child of the family (biological child) would actually be “adopted” at the time his father deemed him ready for the responsibility, and presented to society as a huios (son) of the family.
This is what I see when I read that creation eagerly waits with anticipation for the sons of God to be revealed. As the elect, I also believe it is our responsibility and privilege and honor (if we do run the race to win, leaving aside all the hindrances that beset us) to represent our Father’s interests in the continuing transformation of this world into His kingdom. This we cannot do to the fullest extent until we are perfectly trained and have become like our Rabbi, Jesus.
So I agree with those who say that we are also a kind of firstfruits. Jesus was raised on the Feast of Firstfruits, and the church was born at Pentecost, when the second firstfruits offering was presented. But there is more of the harvest yet to be brought in, and if the firstfruits are holy, then so is the entire production of the soil.
Love, Cindy