A good question to ask in order to gauge the importance of an issue is, "How closely related is this issue to the Gospel?" Some would probably accuse me of hijacking the Gospel if I related it too closely to gender issues. After all, gender has nothing to do with the forgiveness of sins, reconciliation, or substitutionary atonement. Being egalitarian or complementarian is not something that determines our eternal destiny as adopted children of God. Praise God this is true! Yet, a more penetrating question may be, "Do we stand to lose something of the Gospel if egalitarianism is assumed?" In my opinion, the overwhelming answer is Yes.
A biblical test-case can be seen in the flow of thought of Ephesians. The first two chapters show the general/universal understanding of the Gospel. The Gospel is, most fundamentally, God's plan of redemption on behalf sinners through Christ. Readers of this letter must, first and foremost, come to terms with Paul's emphasis on the Gospel being God's work despite human sinfulness. Other than faith, Paul doesn't attribute anything to the human sinner in the effectiveness of the Gospel. In fact, many argue that the entire phrase "For by grace you have been saved through faith" (2:8) is the "gift" that 2:9 is referring to. The conclusion of chapters 1-2 is that there is nothing peculiar about any individual sinner that would cause them to be the darling of God's saving work. Rather, as 2:4-5 tells us, salvation is to be attributed to the richness of God's mercy.
Chapter 3 of Ephesians affirms this conclusion. What God has revealed in Christ is redemption, not only for covenant Israel, but for Gentile sinners as well. If racial status cannot keep us away from the love of Christ, it is easy to conclude that social status, age, wisdom, or gender cannot either. And we see that the rest of the New Testament affirms this same conclusion. The Gospel is for all those - every tongue and tribe - who repent of their sins and believe in the Gospel. Praise God for his infinite wisdom!
Interestingly, Paul does not end his letter with chapter 3. He knows that when the Gospel is believed, it is the power to change the life of the Christian. In other words, after one is forgiven of their sins and saved from the wrath to come, the Christian life cannot be simply reduced to moralism. Rather, the Gospel radically shapes how we live and make choices. So, for example, he writes at the end of chapter 4, "Be kind to one another, tenderhearted, forgiving one another as God in Christ forgave you." And also 5:2, "And walk in love, as Christ loved us and gave himself up for us, a fragrant offering and sacrifice to God." Paul exhorts his readers to forgive one another and walk in love not because that is how we need to get along until Christ comes back, but because God in Christ loved and forgave us. Paul bases his Christian ethic on the cross of Christ. Interestingly, Paul's command to walk in love and forgive one another is still as universal as the Gospel. All those who are redeemed in the Lord are to love and forgive one another and even submit to one another.
However, Paul begins to apply the Gospel at a more particular level at the end of chapter 5. Up until this point, Paul displays how the Gospel functions universally to change the lives of Christians. Yet, from 5:22-6:9, Paul shows how the Gospel applies in particular to husbands, wives, parents, children, slaves, and masters. At a very significant level, the Gospel applies to a wife differently than it does to her husband. The Gospel informs a husband of God's design for him as a man in a way that is different than the wife. Interestingly, the Gospel does not blur gender distinctions, but, rather, gives them definition. Our identity as men and women and how we relate to one another is informed by God's saving work in Christ Jesus.
If egalitarianism is assumed, there are at least two aspects of the Gospel that we lose. Both are significant.
First, marriage, throughout Scripture, is used to portray God's saving promises and his covenant faithfulness to his people. If we lose the important distinctions between the roles of husbands and wives in marriage, then we lose a significant biblical understanding of God's work in Scripture and in redemptive history.
Second, a central concern of Paul in all his letters, especially Ephesians, is not only Gospel clarity, but also how the Gospel applies to the Christian life. If we have confusion as to how men and women ought to act and fulfill divinely intended roles in the Church, marriage, and family, then there will be confusion as to how to apply the Gospel to the Christian life. As we see in Ephesians 5, God has particular applications of his Gospel that are gender specific. If we lose the gender specificity, then we lose a divinely intended Gospel application.