And while the crowds were thickly gathered together, He began to say, “This is an evil generation. It seeks a sign, and no sign will be given to it except the sign of Jonah the prophet.  For as Jonah became a sign to the Ninevites, so also the Son of Man will be to this generation. Luke 11:29-30 (NKJV)

In this passage, Jesus refers to the sign of Jonah and the sign of the Son of Man. Jonah actually became a sign from God to the people of Ninevah, being spit out onto the shore by a great fish. Jesus actually became a sign to the world when He was raised from the dead. Jonah and Jesus didn’t just perform signs- they BECAME signs.

A sign is a means of proving something to people who do not believe in it or are ignorant of it. The very survival of Jonah was proof to the Ninevites that God wanted them to repent. Jesus’ life, death, burial and resurrection serves as proof to sinners that God is real and wants to be in relationship with them.

In the same way, we become signs to unbelievers that God is real and can do mighty things in their lives. As the Holy Spirit transforms us, and people begin to see the difference in us, it serves as proof that the Lord is real, and that He can change their lives too. And as God works in our lives and others see how He brings us through trials and troubles, we prove that the peace of God and the power of God are real. We are called to have signs and wonders following us, but it even more wonderful to be a signpost for God, pointing others to Jesus Christ.