Three important observations discredit this popular argument. First, Paul compares the relationships among Jews and Greeks, slaves and free, and men and women in only one common area: the status distinction these created in one’s relationship to God. He declares that everyone stands on a level before the cross.
Second, in other areas Paul recognized that the distinctions among the three relationships still existed. Being one in Christ did not change a Jew into a Gentile, a slave into a freeman, or a man into a woman; rather, it changed the way each of these related to the other.
Third, there is an important difference between Paul’s view of the man-woman relationship and his view of the slave-freeman relationship. While Paul defends the subordination involved in the man-woman relationship by appealing to the order in which man and woman were created, he never teaches that slavery is a divine institution, a part of God’s order of Creation and should be perpetuated. On the contrary, he encourages the slave when offered the opportunity of emancipation to take advantage of it (1 Corinthians 7:21), and he classifies slave-kidnappers among the “unholy and profane” (1 Timothy 1:9, 10). While slavery is a temporary human institution resulting from the Fall, male-female differences are unchangeable biological distinctions originating from Creation.
– Adventist Affirm, Answers to Questions about Women’s Ordination – Ordination of Women and Paul