The main reason the disciples believed in the resurrection of Jesus is that they saw Him alive after He was dead. Jesus presented Himself alive on a number of different occasions to His followers.
Thus we see them testifying, time and time again, to the fact they were eyewitnesses of His resurrection. This firsthand evidence of the disciples is a powerful argument for the resurrection of Christ. The disciples knew that He had risen because they saw Him with their own eyes.
Jesus' Testimony About His Resurrection
First, we have Jesus' own personal testimony is that He was raised from the dead.
I am the Living One; I was dead, and behold I am alive for ever and ever! And I hold the keys of death and Hades (Revelation 1:18).
Luke records Jesus' saying.
Look at my hands and my feet. It is I myself! Touch me and see; a ghost does not have flesh and bones, as you see I have (Luke 24:39).
The Various Appearances Of Jesus
Many different people saw Jesus after the resurrection. The appearances were as follows.
The first appearance of Jesus was to Mary Magdalene.
Now when she had said this, she turned around and saw Jesus standing there, and did not know that it was Jesus. Jesus said to her, 'Woman, why are you weeping? Whom are you seeking?' She, supposing him to be the gardener, said to him, 'Sir, if you have carried him away, tell me where you have laid him, and I will take him away.' Jesus said to her, 'Mary!' She turned and said to him, 'Rabboni!' (which is to say, Teacher) (John 20:14-16).
This appearance was totally unexpected.
Mary The Mother Of James, Salome, And Joanna
Jesus also appeared to these three women. This happened after the appearance to Mary Magdalene. After an angel told them Jesus had risen, they were on their way to tell Jesus' disciples when they met the risen Christ
And behold, Jesus met them and greeted them. And they came up and took hold of his feet and worshiped him (Matthew 28:9).
Again, we have another unexpected appearance. As was true with Mary Magdalene, these women touched the body of Jesus.
Peter is the first person mentioned in Paul's list of witnesses, and is the first of the apostles to see the risen Christ. This was a private appearance to reassure him, since he had just denied his Lord. The gospels are completely silent as to the details of this meeting. Luke merely wrote:
The Lord is risen indeed, and has appeared to Simon! (Luke 24:34).
Two Disciples On The Emmaus Road
Later on Easter Sunday, Jesus appeared to two disciples on the road to Emmaus.
And behold, two of them were going that very day to a village named Emmaus, which was about seven miles from Jerusalem. And they were conversing with each other about all these things which had taken place. And it came about that while they were conversing and discussing, Jesus himself approached, and began traveling with them. But their eyes were prevented from recognizing him (Luke 24:13-16).
As was true with the women, these two disciples were not expecting Jesus to rise. In fact, they were leaving Jerusalem because they had lost hope in Him.
The Disciples - Thomas Absent
This is the last of the five appearances of Jesus on Easter Sunday. It took place in the evening, probably in the upper room in which Jesus had instituted the Lord's Supper. It is recorded in both Luke's and John's gospel, giving us two independent accounts as to what happened. John wrote:
When therefore it was evening, on that day, the first day of the week, and when the doors were shut where the disciples were, for fear of the Jews, Jesus came and stood in their midst, and said to them, "Peace be with you." And when he had said this, he showed them both his hands and his side. The disciples therefore rejoiced when they saw the Lord. . . But Thomas, one of the twelve, called Didymus, was not with them when Jesus came (John 20:19,20,24).
All Of The Disciples
Eight days later He appeared again - this time with Thomas present.
And after eight days his disciples were again inside, and Thomas with them. Jesus came, the doors being shut, and stood in the midst, and said, 'Peace to you!' Then he said to Thomas, 'Reach your finger here, and look at my hands; and reach your hand here, and put it into my side. Do not be unbelieving but believing.' And Thomas answered and said to him, 'My Lord and My God!' (John 20:26-28).
Seven Disciples At The Sea Of Galilee
Another appearance was to seven disciples on the Sea of Galilee.
After these things Jesus manifested himself again to the disciples at the Sea of Tiberias, and he manifested himself in this way. There were together Simon Peter, and Thomas called Didymus, and Nathanael of Cana in Galilee, and the sons of Zebedee, and two other of his disciples (John 21:1, 2).
A Mountain In Galilee
There is also the account of Jesus appearing before His eleven disciples in Galilee.
But the eleven disciples proceeded to Galilee, to the mountain which Jesus had designated. And when they saw him, they worshiped him; but some were doubtful (Matthew 28:16,17).
Over Five Hundred People
On another occasion, Jesus appeared to over five hundred people at one time.
After that he was seen by over five hundred people at once, of whom the greater part remain to the present, but some have fallen asleep (1 Corinthians 15:6).
Scripture also says that Jesus appeared to His half-brother James.
Then he appeared to James, then to all the apostles (1 Corinthians 15:7).
The details of this appearance are not recorded.
After Jesus' ascension He appeared again - this time to Saul of Tarsus.
And as he [Saul] traveled he came near Damascus, and suddenly a light shone around him from heaven. Then he fell to the ground, and heard a voice saying to him, 'Saul, Saul, why are your persecuting me?' And he said, 'Who are you, Lord?' And the Lord said, 'I am Jesus, whom you are persecuting' (Acts 9:3-5).
These are the appearances of Jesus that the New Testament records. They caused His disciples to believe that He had risen from the dead. Luke says that Jesus showed Himself alive with many convincing proofs.
To these he also presented himself alive after his suffering, by many convincing proofs, appearing to them over a period of forty days and speaking of the things concerning the kingdom of God (Acts 1:3)
The Bible says that Jesus made a number of appearances after His death. They were to a number of different people over a forty-day period. The Bible specifically says that on Easter Sunday Jesus appeared to Mary Magdalene, the women that came to Jesus tomb (Mary the Mother of James, Salome, and Joanna), Peter, and two disciples on the Emmaus road. He also appeared to the remainder of the Twelve Disciples with Thomas absent. Later he appeared to them with Thomas present. There was also an appearance to seven disciples on the Sea of Galilee. On another occasion he appeared to over five hundred people at the same time. There is also an appearance to James. Finally Jesus appeared to Saul of Tarsus - the man who became the Apostle Paul. These appearances convinced His disciples, beyond any doubt, that He had risen from the dead.