Our Lord Jesus Christ teaches us to humble ourselves in four ways.
Chapter 91

The Son of God speaks to Saint Birgitta and says: 'You ought to humble yourself in four ways. First, against them who have power by rank or by office in the world. For since man has come to despise and leave off obeying God, it is worthy that he at least obey man. And because people must not be without rulers, therefore reverence and praise must be given to their power. Second, you must humble yourself towards those who are spiritually poor, that is to say, towards sinners, praying for them and thanking God for the ways you are not nor have been any such.
Third, towards them who are spiritually rich, that is to say, towards the friends of God, thinking yourself unworthy to serve them or to be conversant amongst them. Fourth, towards the poor of the world, by helping them and clothing and washing their feet'.