To say that a person is spiritual would imply that the person is closely in union with God.
It may also imply that God may choose to reveal certain things through that person.
In the 1st reading, Balaam was a spiritual person and as well as a prophet of God.
But he was enticed with a reward by the enemies of Israel to lay a curse on Israel so that they will be defeated in battle.
In other words, he detracted from his prophetic role and even collaborated with the enemies of Israel.
But the Spirit of God came upon him and he submitted to the authority of God and retracted and declaimed his curse.
And he even blessed Israel as well as prophesied that a great leader would arise from Israel.
In the gospel, when the chief priests and elders questioned Jesus about His authority, He in turn questioned them about the authority of John the Baptist.
If the chief priests and elders had been spiritual enough, they would have acknowledged that the authority of Jesus and John the Baptist was from above.
We are called to be a prophetic people and to fulfil that prophetic role, we have to be spiritual and to be closely united with Jesus.
And when we speak, may it be Jesus who speaks through us, and may our words be a blessing for others.