I'm tempted to say, "Yes, of course it is!" and be done with it. Because, truth be told, if we are to judge Christianity by Groothuis's hyper-logical paradigm, it is. And it has to be because the central icon of Christianity is "sexist". In marriage, a wife is to submit to her husband as the Church submits to Christ and a husband is to give himself for his wife as Christ gave himself up for the Church. Marriage presents the Church and our relationship to Jesus Christ in microcosm. Unless Groothuis wants to accuse our Lord, his Apostles and the Church as guided by the Holy Spirit for virtually her entire history of the "mistreatment of half the human race" he should re-think his advocacy of feminism. Because the Church, following the dominical practice, has never ordained women to the presiding office.
The poison of the feminist paradigm doesn't stop there. It compels him on to skirt around something that sounds dangerously close to denying God the Father as Father. "...Jesus called God his Father not to emphasize masculinity against femininity but to highlight that God is a personal and powerful being." Groothuis is right that Jesus did not call God his Father to emphasize one sex over the other. But he is quite wrong, so very dangerously wrong, when he goes on to claim it was to show that God is a personal being. On the contrary, Jesus called his Father because He is Father. According to Paul in Ephesians 3, human fatherhood derives from God's divine Fatherhood. Of course the Apostles already knew how to pray to the Father, as Christ taught. In fact, while God does exhibit motherly care and the actions we associate with motherhood, He is always Father, never mother.
The feminist wish to avoid acknowledging God's fatherhood and his establishment of patriarchy in creation results in a third error which is at least a near-heresy, a form of neo-modalism wherein Jesus's maleness is held to be incidental and not essential. Both Groothuis and his wife (see Rebecca Merrill Groothuis, Ch, 18 of Discovering Biblical Equality) make the case for their paradigm by referring to Jesus Christ's humanity as if humanity is some sort of generic foundation upon which specific male and female characteristics are overlayed. It is not. In the beginning, we are told, God made them male and female. Both male and female are made in God's image (hence our ontological equality) but we are always either male or female (hence our teleological distinctions). Jesus's maleness is important because his taking on human flesh is important and that human flesh was and is male.
The feminists have to jump through so many hoops, I wonder they don't tire of it and have done with Christianity altogether. The have to pretend patriarchy is a result of the Fall and that Adam's creation first, with Eve being create for him, from him and being brought to him tell us nothing about how men and women are to relate in marriage. They have to pretend that Israel was established as a patriarchy because of the surrounding culture and that it was not due to God's sovereign choice and that the Bridal imagery shot throughout the entire Old Testament teach us absolutely nothing about how men and women are to relate and how authority among God's people is to look. They have to pretend that poor Jesus just had to come to us as a baby boy because women were so devalued and that He did not come, as the Scriptures say, in the fullness of time. Need I go on?
I am glad Christianity is sexist. I am glad I have a Father in heaven who cared so much about me and you and every feminist out there, that He sent his Son who died to save me. Even though I will likely never marry, I am glad for all the beautiful bridal and marital imagery in the Bible. I won't have my own wedding reception but one day, if I am found faithful, I will sit at the wedding feast to end all wedding feasts. I am glad that I am different from a man and that even though I could not bear children of my own body, I am a mother of a different sort. I recently received the highest compliment I think I could ever have paid to me when a young mom and sister in the Lord referred to me as a "mother in Israel".
It wasn't always so. Many of you know that I once embraced the lie that Doug and Rebecca Groothuis introduced me to. It is only by the grace of God that I have repented of that heresy.
I am sure there are many fine chapters and sections in the book and that it is a useful reference. But beware the poison of feminism that runs through it.