I'm equating acting like an adult with accepting responsibility for our actions. Saying that we don't have to worry about consequences and should let God decide is childish.
It's a dangerous idea to refuse to plan or take action because we put something in God's hands. We do the best we can and then put the rest into God's hands.
But if we consider children outside of our planning or action, then fertility treatment and adoption should be rejected as well.
Actually, those Christians who are consistent with Natural Law also reject artificial insemination.
Adoption is consistent with Natural Law.
Saying that we don't have to worry about consequences and should let God decide is childish.
Believing in Divine Providence is childish? Maybe in one regard:
"And he said: "I tell you the truth, unless you change and become like little children, you will never enter the kingdom of heaven."
-Matthew 18:3
I agree with you about fertility treatment since I agree with Catholic teaching on that subject.
I suggest you read Humanae Vitae. To me it is astounding how prophetic that encyclical is.
The purpose of marital sex is both unitive and procreative. There are times when in a marriage that continence is advisable for either health or other reasons, including the spacing of children. For this reason the Catholic Church permits Natural Family Planning, with the caveat that couples are to remain open to life.
The prevalent cultural attitude (not yours) is that pregnancy is an error that must either be prevented or when that fails aborted. I am convinced that the widespread acceptance of artificial contraceptives has lead to this attitude.
There are other fruits of separating the unitive and procreative aspects of married love. The ones which we Christians are most concerned with is the view amongst too many that homosexual behavior and abortion are no longer always sinful.
If sterility (not that cause by medical condition)is a good and positive outcome to be sought in sexual relations. And if the chief purpose of sex is solely unitive. How can we argue against committed homosexual unions without resorting to strictly Biblical truths that too many in this society is nonsense.
Or does the teaching that is expounded upon in the Bible a Truth that is universal? I think it is.
But for Christians the main argument remains Scriptural and what we learn about marriage from Scripture. From that I believe that Christian marriage is a reflection of the Trinity and its life giving constant love.
I think you can find non Catholic sources on this aspect of Christian marriage. All we do is for the Glory of God. How does the use of artificial birth control glorify God? Or does it reflect a stubborn desire to serve our own will instead of His? Remember that the outcome of fertile sex is a child. A child which we are called to rear up for a crown in heaven.