After Jesus died and his body was placed in the tomb, he could have ascended to heaven without appearing to anyone. But Jesus rose and he appeared to his disciples, and he did so for a number of very important reasons.
Triumph and Victory. The Resurrection was emphatic proof that Jesus had decisively and convincingly conquered sin and death.
Glorification. God raised Jesus to glorify him. God was pleased that Jesus had become obedient, even unto death on the Cross, and to praise him, God greatly exalted him with the name above every other name (see Phil 2:8,9). Furthermore, the Father bestowed additional glory upon his Son by exalting him with a place at his right hand (Acts 2:33).
Fulfillment. Jesus had foretold that he would rise from the dead: “And three days after his death he will rise” (Mk 9:31; see also Mt 16:21; 17:23; 20:19; Mk 8:31; 10:34; Lk 9:22; 18:33). When Jesus rose, he proved that all that he had promised was reliable and true.
Reconciliation. The disciples estranged themselves from Jesus when they fled and abandoned their Master at the time of his arrest (see Mt 26:56 and Mk 14:50). Moreover, they did not testify on his behalf at his trial, were absent during the crucifixion, and when it came to being faithful friends, they were miserable failures. Jesus rose so he could forgive them and reestablish a positive relationship with them. Reconciliation was such an urgent necessity that only moments after his Resurrection, Jesus appeared to them and said, “Peace be with you” (Lk 24:36; Jn 20:19,21,26), words that are tantamount to “I forgive you.”
Teaching and Re-instruction. The disciples were still confused about Jesus’ true identity. “They doubted” (Mt 28:17). Jesus rose and appeared to Cleopas and Simeon on the road to Emmaus to reinterpret for them all that referred to him in the scriptures (Lk 24:27; see also Lk 24:45). For forty days Jesus spoke to them about the Kingdom of God (Acts 1:3b).
Faith-Strengthening. After Jesus died, the faith of his disciples continued to waver. Seeing is believing! The risen Jesus appeared in the Upper Room and said, “Look at my hands and my feet” (Lk 24:39) to confirm and strengthen their faith. Jesus showed himself to Thomas (Jn 20:27) so that, with faith strengthened, he could make his profession of faith, “My Lord and my God” (Jn 20:28). “For many days he appeared to those who had come up with him from Galilee to Jerusalem” (Acts 13:31; see also Acts 10:41 and 1 Cor 15:5-8).
Commissioning. Jesus rose to commission his disciples. He told them, “Go into the whole world and proclaim the gospel to every creature” (Mk 16:15); “make disciples of all nations,” “baptizing them,” and “teaching them” (Mt 28:19,20). He also instructed Peter [and the others] to “Feed my lambs” (Jn 21:15), “tend my sheep” (Jn 21:16), and “feed my sheep” (Jn 21:17).
Reassurance. Jesus rose so that he could reassure his disciples that even though he would ascend to heaven and be physically absent, he would always be their constant companion: “I am with you always, until the end of the age” (Mt 28:20b).