What about women serving as pastors? It seems clear that the office of pastor/elder/overseer is intended by God to be held by men:
It is a trustworthy statement: if any man aspires to the office of overseer, it is a fine work he desires to do. An overseer, then, must be above reproach, the husband of one wife (1 Tim. 3:1-2; emphasis added).
For this reason I left you in Crete, that you might set in order what remains, and appoint elders in every city as I directed you, namely, if any man be above reproach, the husband of one wife (Tit. 1:5-6; emphasis added).
Paul does not expressly say that women are forbidden from holding the office, and so we might exercise a little caution in making an absolute blanket conclusion. It seems that there are numerous very effective female pastors/elders/overseers around the world today, particularly in developing nations, yet they are still the overwhelming minority. Perhaps God does occasionally call women to this role when it serves His wise kingdom purposes or when there is a shortage of qualified male leadership. It is also possible that many of the female pastors in the body of Christ today are actually called to other ministry offices that are biblically valid for women, such as the office of prophetess, but current church structure only allows them to function in a pastoral role.
Why is the office of pastor/elder/overseer reserved for men? Understanding the function of that office might help us to understand. One of the scriptural requirements for the pastor/elder/overseer is that,
He must be one who manages his own household well, keeping his children under control with all dignity (but if a man does not know how to manage his own household, how will he take care of the church of God?)” (1 Tim. 3:4-5).
This requirement makes perfect sense when we realize that the New Testament elder oversaw a small house church. His role was similar to that of a father overseeing his household. This helps us to understand why the pastoral office should be held by a man—because it so closely resembles the family structure which, if it is in line with God’s design, should be headed by a husband, not a wife. More on this later.