I appreciate Steven questioning me. It helps me to define my reasons for all, even myself. I will respond to some of his objections here.
It is not clear to me that to do something such that, if you were not to do it, you would receive a blessing from God is sinful. Suppose children are a blessing from God, as scripture teaches: why is it supposed to follow that if you don't want one, you are sinning?
That's not the only point. Not only is this blocking a blessing from God, but in performing the act and removing the possibility of the whole point of the act, you are acting against the natural reason for which the act was created for. You are not making the intended end of sex, which is union with your spouse and children, the goal of the act. The end of sex in the case where children are actively prevented becomes nothing but pleasure for selfish reasons, in my opinion. If someone doesn't want to have children, there are natural ways to prevent this that wouldn't be morally questionable, most notably abstinence (for a time at least).
I suppose being taken away into heaven would be a blessing; for Christians, to die is gain, as Paul tells us. It is a blessing from God for a Christian to be taken away from earth and to be with Christ. But is it therefore sinful if we do not desire this, for pragmatic concerns or otherwise?
Yes, upon death we will be better off than we are, but this does not mean we seek death, or that death itself is a blessing. Death is an enemy that we are to avoid (1 Corinthians 15:26) and only happens as a result of the sin we have committed. Furthermore, Paul did say that death would bring him into the presence of the Lord, but he would be removed from his intended end on earth, the propagation of the Gospel.
Hopefully that also addresses his next couple of paragraphs.
It also seems to me that if you really think you are sinning by behaving in such a way as to prevent yourself from receiving some blessing of God's
Ah, but as we see, death is not a blessing, but the enemy. We should not attempt to quicken our death because it is the curse for sin in this life, and would remove us from spreading the Gospel and advancing the kingdom of God. God will remove us in His time.
Say you and your wife are exceptionally poor
In this case I think modern Christians have forgotten who provides for them. God will provide what we need if we trust Him. I therefore don't think the "not enough money" argument is very good in light of God's promises. Joseph and Mary were not wealthy, yet God provided for them.
If you have sex with your wife, knowing that there is a high chance she will conceive, and that you will be having a baby in those conditions, it seems to me that is the height of irresponsibility
Which is why there are other natural options that do not require twisting the true and natural purpose of sex; which is union with your spouse in love and children. Preventing the possibility of children seems to be working against God and questioning His provision in your life. Furthermore, is anyone really ever "financially ready" to have children? God will provide.
I think it's important to note, as I have in the past, that up until the 1930's, all of the greatest minds of Christianity believed that contraception was a sin. This doesn't make it necessarily so, but I think it adds weight that needs to be considered. Also, birth control is a progressive idea. It arose because of the degrading of the sanctity of life in the progressive agenda, and the false belief that having children is destroying and overpopulating the planet. Margaret Sanger, the earliest proponent of birth control, was a eugenicist and founded Planned Parenthood which is the largest abortion provider in the nation. The modern church has justified it in other ways.
The main reasoning behind contraception seems to be about me wanting to have more time, about me wanting more money for myself, and about me not wanting to be inconvenienced. I don't think these are adequate reasons to prevent the natural course from being taken. I don't think children are an inconvenience. The ancient Jew and Christian would be incensed at the idea, as they trusted God to provide what they needed.