At the end of Mark's Gospel, the Lord strongly calls us to believe. Jesus' disciples refused to believe the resurrection-witness of Mary Magdalene or that of the two disciples who met the risen Jesus on the road to Emmaus (Mk 16:11, 13). So Jesus "took them to task for their disbelief and their stubbornness, since they had put no faith in those who had seen Him after He had been raised. Then He told them: 'Go into the whole world and proclaim the good news to all creation. The man who believes in it and accepts baptism will be saved' " (Mk 16:14-16).
At the end of Luke's Gospel, the Lord said: "How slow you are to believe" (Lk 24:25). Then Jesus "opened their minds to the understanding of the Scriptures" (Lk 24:45), for "faith comes through hearing and hearing by God's word" (Rm 10:17, our transl).
At the end of John's Gospel, Jesus said to Thomas: "Do not persist in your unbelief, but believe!" (Jn 20:27) Thomas responded by making the great act of faith in Jesus as Lord God (Jn 20:28). John concludes: "These have been recorded to help you believe that Jesus is the Messiah, the Son of God, so that through this faith you may have life in His name" (Jn 20:31).
Jesus commands us to be His resurrection witnesses. Without faith we cannot do this. But in faith we "cannot help speaking of what we have heard and seen" of the risen Christ (Acts 4:20).
On this Easter day, turn to the risen Christ and cry out: "I do believe! Help my lack of faith!" (Mk 9:24, our transl)