Maybe instead of saying "Slaves obey your earthly masters" Jesus should have said "Slave owners release your slaves!". Much like with Paul saying "A woman should not be permitted to teach" should have said "Women and Men should be seen as equals." But you know... I'm sure it was all very confusing.
The whole tone of Church teaching in regard to woman is, to the last degree, contemptuous and degrading. - Elizabeth Cady Stanton