Did you skip right past, "he wasted his seed on the ground in order not to give offspring to his brother" (even though you bolded it)? He went and had sexual intercourse with his dead brother's wife - in essence agreeing to marry her, else the sex was a sin - but then pulling out to ejaculate because he didn't want to have a child and it be considered his brother's! If we read this the way those such as you do, would that mean a man or boy who has "wet dreams" is committing a sin? Is EVERY instance of semen being some place it isn't supposed to be a sin? Are you actually telling a husband and wife that their act of mutual masturbation is a sin? That they can never have "oral sex" because they will go to hell?!
I think this is a good example of why the "church" should stay out of the marriage bed of its members. Teaching them what Scripture says about marriage and the responsibilities they each have to the other, what God's laws are concerning sex outside of marriage, even going into talking about bringing children into the world and their job to bring them up in the nurture and admonition of the Lord, all that's fine. I think also a pastor should address social issues of the day and how Christians are to see the world through the eyes of the Lord and it would include abortion and the need for Christians to stand up against the moral evils of the day. But, seriously? Your priest sitting you down and giving you a list of what a man and wife can and cannot do in their own bedroom? That's too much and it only proves that a church oversteps its bounds when it tries to do this because of the very fact that few church members OBEY them.
You can think whatever you want about what "spirit" leads me, it doesn't matter because I know who my redeemer is and His Holy Spirit lives within me convicting me when I sin and leading me on the paths of righteousness for His name's sake. I would NEVER presume to tell you what spirit you follow, why do you imagine you can tell me or judge that I don't follow the Holy Spirit? Has this power trip of dictating to couples what they can do in the privacy of their bedroom gone to your head???
I just showed you what the punishment was for refusing offspring to the dead brother's wife. Its public humiliation. See Deuteronomy 25:5.
Therefore, taking Onan's life was not because he refused to fulfill the Levirate law. For that he would have simply been publicly humiliated.
No, taking Onan's life was for coitus interuptus, and EVERY Christian until 1930 agreed that was the case.
Since all of Christianity has been unanimous up till now about the immorality of contraception, the onus is on the innovators, those preaching this new gospel, to somehow PROVE that all Christians up till 1930 were incorrect in their interpretation of the Onan incident. That you have not done because it cannot be done.
Preach it, sister!!