The Apostle Thomas had the opportunity to become the very first believer. But he blew it.
We read about this in John 20:24–25:
Now Thomas, one of the twelve, called the Twin, was not with them when Jesus came.  So the other disciples told him, “We have seen the Lord.” But he said to them, “Unless I see in his hands the mark of the nails, and place my finger into the mark of the nails, and place my hand into his side, I will never believe.”
The women and the other disciples had all seen Jesus alive. They no longer needed faith because they had seen with their own eyes that Jesus had risen. They had seen his scars, his hands and his feet and his pierced side.
They tried convincing Thomas that Jesus was alive but to no avail. He responded with those memorable words, John 20:25 “Unless I see in his hands the mark of the nails, and place my finger into the mark of the nails, and place my hand into his side, I will never believe.”
He could have become the first true believer – to believe in Jesus’ resurrection from the dead without actually seeing it – but he blew it.
He did, however, become the very first confessor.
Eight days later, his disciples were inside again, and Thomas was with them. Although the doors were locked, Jesus came and stood among them and said, “Peace be with you.”  Then he said to Thomas, “Put your finger here, and see my hands; and put out your hand, and place it in my side. Do not disbelieve, but believe.”  Thomas answered him, “My Lord and my God!”
After he had seen Jesus all of Thomas’ doubts were removed and he boldly confessed, “My Lord and my God.”
This has been the church’s confession ever since. Yes we have had to clarify things and come up with more detailed confessions of faith such as the Apostles’ Creed and the Nicene Creed, but they all boil down to Thomas’ simple confession: Jesus is Lord and God.
When we confess the creeds then we are simply saying as Thomas did that Jesus is my Lord and my God.
The word “my” is so important. Jesus is and always will be Lord and God. The only question is if we confess him as my Lord and my God.
As Jesus tells Thomas, John 20:29
 Jesus said to him, “Have you believed because you have seen me? Blessed are those who have not seen and yet have believed.” (ESV)
Peter has a lot to say about faith in the first chapter of his first epistle.
He describes the essence of faith: “Though you have not seen him, you love him. Though you do not now see him, you believe in him and rejoice with joy that is inexpressible and filled with glory,  obtaining the outcome of your faith, the salvation of your souls.” (I Peter 1:8-9)
Peter was an eyewitness but the people to whom he is writing were not eyewitnesses. Yet they had faith: “Though you do not now see him, you believe in him and rejoice with joy that is inexpressible and filled with glory.”
He also points out that our faith is more precious than gold.
 In this you rejoice, though now for a little while, if necessary, you have been grieved by various trials,  so that the tested genuineness of your faith—more precious than gold that perishes though it is tested by fire—may be found to result in praise and glory and honor at the revelation of Jesus Christ. (I Peter 1:6-7)
Gold is precious. Many people want as much of it as they can get. It is not only great for jewelry but during uncertain economic times gold is valuable because it will never lose its value.
Gold is also very tough. When it is exposed to fire it does not burn up. Instead fire is used to remove impurities from gold making it even more valuable.
The same is true of our faith.
Just as gold is purified through fire, our faith is purified by various grievous trials. Often when trials come we think God is angry with us or that there is something wrong with our faith. That is not the case at all. Fiery trials come because God is working to purify our faith.
So faith and gold are similar but there is an important difference between them. Gold perishes. It’s fine to accumulate gold but we must keep in mind that ultimately, like all the things of this world, it will perish.
That cannot happen to our faith. Our faith does not perish. It does not perish because it is based on the resurrection of Jesus from the dead. Our faith is a death-defying faith.
In Acts 5 the Jewish leaders were trying to decide what to do with the Apostles who kept preaching about Jesus. One of them by the name of Gamaliel advised them to wait and see. He pointed out that other leaders had arisen who had gathered followers but then these leaders had been killed and their followers were dispersed.
So Gamaliel advised his fellow Jews just to leave the Apostles alone. If their movement was based on human power it would fail. If, however, it was from God they would not be able to overthrow it.
The Jewish leaders initially took Gamaliel’s advice and left the Apostles alone but then they could not help themselves and started opposing the Apostles of Jesus with all their might. But eventually they failed and the Gospel of Jesus Christ, based on his triumphant resurrection from the dead, was spread throughout the whole world, first by the eye-witnesses and later by the believers.
Thomas blew it when he was given the opportunity to become the very first believer, the very first person to believe that Jesus was alive without actually seeing him alive. But he did become the very first person to be a confessor, to confess the truth that Jesus is my God and my Lord. Still today we confess the same eternal truth; our risen Lord Jesus is our Lord and our God.