Haggai 1:15 - 2:9 / Luke 9:18-22
The ministry of prophets was a main feature in the Old Testament.
God spoke to His people through the prophets, and the prophets themselves had no reservation whatsoever that they were indeed proclaiming an oracle from the Lord God.
Such was the case in the 1st reading. Taken from the book of the prophet Haggai, the prophet himself said that the word of the Lord was addressed to him.
He was told what to say, who to say it to, and to say it with the authority of the Lord God.
So in the Old Testament, the prophet spoke the unmistakable word of God, and with it the people knew the will of God and the direction to take.
The last of the Old Testament prophets was Malachi, and until John the Baptist appeared, there was no prophetic voice for more than 400 years.
And when Jesus appeared preaching and proclaiming the Kingdom of God with authority and power and healed the sick and cast out demons, the people saw Him as a prophet.
Presumably, the people would expect Jesus to proclaim good news, like liberation from their oppressors, and freedom and independence.
And yet He told His disciples that He was destined to suffer grievously, to be rejected by the elders and chief priests and scribes, and to be to put to death, and to be raised up on the third day.
That sounds depressive. But if we believe that it is the prophetic voice of God, then we will accept the sufferings of life, and at the same time we will also believe that God will raise us up from our sufferings, just as He raised Jesus from the dead.