Matthew 16:1-4 (NIV)
1The Pharisees and Sadducees came to Jesus and tested him by asking him to show
them a sign from heaven. 2 He replied, "When evening comes, you say, 'It will
be fair weather, for the sky is red,' 3and in the morning, 'Today it will be
stormy, for the sky is red and overcast.' You know how to interpret the
appearance of the sky, but you cannot interpret the signs of the times. 4 A
wicked and adulterous generation looks for a miraculous sign, but none will be
given it except the sign of Jonah." Jesus then left them and went away.

The Pharisees and Sadducees were always out to get Jesus, so they asked him to
produce a sign from heaven to prove who He was. He gave a response they already
looked for signs that were not even of God to predict the weather. And yet they
had the word of God that showed an unrighteous city turned to God for their
sins and they were ignoring the sins of the present day.

There is an old adage that says, "Red sky at night, sailor’s delight. Red sky
in morning, sailor’s warning." In Shakepears play, VENUS and ADONIS there is a
line, "Like a red morn that ever yet betokened, Wreck to the seaman, tempest to
the field, Sorrow to the shepherds, woe unto the birds, Gusts and foul flaws to
herdmen and to herds.” There is "some" amount of scientific truth around the
2000 year old idea to predict the weather by the red sky. The problem is many
people will take the "old adage" as truth to their heart and ignore the truths
of God. It's exactly what Jesus was telling the Pharisees and Sadducees. They
were looking for the wrong things. They should have been looking for what God
was to change their hearts and the hearts of others. They should have been
looking for a revival, a cleansing of sin, but instead they just wanted to see
miracles. Pray that God would start a revival in your heart and that it would
spread to others. Pray to seek God and know He is real and living; and that you
would not need signs or miracles to know of His existence.