Note 15 at Rom. 14:20: Prior to this verse, Paul had encouraged the believers to consider their weaker brothers based on their obligation to love one another (see note 2 at Rom. 13:8, p. 835). Now he strengthens that argument by revealing how damaging it could be if the weaker brother follows our actions with a defiled conscience. It is evil for him (v. 20), it will offend him and make him weak (v. 21), it will damn him, and it is sin for him (v. 23).