Luke 20:45 Then in the audience of all the people he said unto his disciples,
Jesus was not afraid to speak the truth in front of his accusers. The Jewish leaders were more interested in not upsetting public opinion. They wanted the praise of men. Jesus speaks the mind of God to his disciples in front of all the people assembled.
Luke 20:46 Beware of the scribes, which desire to walk in long robes, and love greetings in the markets, and the highest seats in the synagogues, and the chief rooms at feasts;
Beware of the scribes. who were supposed to keep the law, but who sought the praises of men, and positions of power over them, rather than to obey God.
Luke 20:47 Which devour widows' houses, and for a show make long prayers: the same shall receive greater damnation.
They had a false religious spirit before men, they were covetous and their deeds were evil. They did not expect the words of Jesus when he said; they will receive greater damnation. Those entrusted with the word, must give account to what they say and do. If they are false they will be judged more severely.
James 3:1 My brethren, be not many masters (teachers), knowing that we shall receive the greater condemnation.
If a greater condemnation is by leading others astray, there is also a greater reward for leading many to God.
Dan 12:3 And they that be wise shall shine as the brightness of the firmament; and they that turn many to righteousness as the stars for ever and ever.
We serve God for his glory, not for our own glory or gain from men.