Commentaries:
If we are gluttonous and encourage or cause others who are weak to be gluttonous, part of the responsibility of their sin rests on us. This puts a great amount of pressure on us to be our brother's keeper, looking after his welfare without judging him.
Martin G. Collins
Gluttony: A Lack of Self-Control (Part Two)
Self-restraint and obedience to God's law is realized in outgoing concern for others that exceeds and rules over our own self-interest. Even lawful acts may on occasion cause other brethren to stumble or be made weak. Self-control provides the ability to resist what may cause pain to others. Thus, we exercise self-control for others, as well as for ourselves.
Martin G. Collins
Self-Control
Other Forerunner Commentary entries containing Romans 14:20:
Matthew 18:6
Mark 9:42