Steve Ray has a list of more than 35 loaded Questions for "Bible Christians" (quotation marks his)(link to the whole list). I originally planned to respond to just 35 of them, but the series seems to have been of interest, so in this extension, I'm responding to three more numbered questions in his list, plus fourteen "bonus questions" that take the form "Where does the Bible say ... ." I'm trying to provide the answers in the same common format as the original series, for easy reference. This is number 2/17.
37) How does a Protestant know for sure what God thinks about moral issues such as abortion, masturbation, contraceptives, eugenics, euthanasia, etc.?
The Reformed believer searches the Scripture and is content with God's revelation of his moral law.
1) Scripture is able to thoroughly equip the man of God for every good work. That speaks to the sufficiency of Scripture to adequately address every moral issue that arises, from abortion to euthanasia.
2) A sufficient answer that adequately addresses the issue may not leave the believer 100% sure on every nuance of every question. However, the believer is content with the revelation he has been given and seeks to apply it to his life as best he can with prayer to God for wisdom.