You are trying to argue from silence, which is not valid. There were thousands of Jews who were saved at Pentecost and shortly thereafter. We hear nothing more about them, but that does not automatically mean that they were unfruitful. The very fact that Nicodemus came to Jesus and then stood up for Him later should be sufficient that the Holy Spirit was working on Him. And while all the disciples fled after the crucifixion, this man did something extraordinary. For all we know, he may have been with Joseph of Arimathea when Joseph approached Pilate for the body of Christ. If that does not tell you anything then you have already pre-judged this disciple of Christ negatively. And we are told not to judge God's servants. They both were probably older men and we really don't know what happened to them,