There are some respects in which every man should rail his house by denying himself those indulgences which might be lawful to others, but which would prove fatal to himself. The individual who knows his weakness to be an appetite for drink should resolve to totally abstain. Every man, I believe, has a particular sin which is a sin to him, but may not be a sin to another. No man's conscience is to be a judge for another, but let no man violate his conscience. If you cannot perform a certain act in faith, you must not do it at all. I mean if you do not honestly and calmly believe it to be right, even if it is right in itself, it becomes wrong to you. Watch, therefore, watch at all points. Guard yourselves in company.
From sermon (No 2999) on Deuteronomy 22:8 "When you build a new house, then you shall make a railing for your roof that you bring not guilt of bloodshed on your household, if any man fall from it."