"Also, we have to examine why a couple would deliberately abstain from having children."
Sure. I'm childfree. Let's go.
"Is it so they can save up to buy a new car or a bigger house?"
I don't want a big house, and I'm ok with my car now. And wouldn't my BF and I need that bigger house if we had lots of kids?
"Is it so the woman won't have to quit her successful career?"
There is no woman--I'm gay. You wouldn't want another queer raising children into the Radical Gay Lifestyle, now would you?
"Is it because the couple can't imagine being burdened with a child?"
No, I can imagine it quite well. That's why I don't want kids.
"If so, these are all highly selfish reasons to avoid having children."
Luckily none of them applied to me. ;)
"The Bible is very clear about rebuking God's will."
The standard liberal Christian interpretation of God's commands to "be fruitful and multiply" is that He was referring to the human race as a whole. In other words, He was telling humans in general to reproduce, not commanding everyone to have children. He even made some of us unable or unwilling to have children, presumably for a reason. For example, people who are unable to conceive can help raise the children of others who reproduce, and people who are unwilling to raise children could fully dedicate themselves to something else for God or humanity.
In any event, God's commands to reproduce are irrelevant now; we were fruitful and multiplied. God was not telling to do so for its own sake; He had a reason--and that reason is what matters, not the command itself. God wanted us to populate the planet to take care of it and ensure our survival. In fact, that now involves curbing overpopulation and reproducing less.
Now doesn't this sound much more reasonable and sensible? Funny thing, that.