There are some things that are defensible in the RC Church's dogmatic teaching on sexuality, such as loyalty and fidelity in marriage; refraining from using sex as a tool of exploitation; encouraging, as much as possible the pursuit of sexual activity in situations where children can grow up safely with committed parents. But these are really just extensions of the universal moral code--to love, to be loyal and faithful, to take care of creation. On the other hand, the Church's declarations on male and female "nature" down to their little tippy toes; its stance on feminism and contraception; and its unwillingness to recognize the value of same-sex relationships do not stand the test of time or science. These teachings deserve to be challenged vigorously, especially since they add little to the moral fabric except "Because I could never get pregnant but I still say so." 

The social gospel holds up much, much better.