Where did Lazarus go between death and resurrection?
Jesus wept for his friend, and prayed for him.
What was the point, if at death all is decided already?
John 11
4 When he heard this, Jesus said, “This sickness will not end in death. No, it is for God’s glory so that God’s Son may be glorified through it.”
John 11
41 So they took away the stone. Then Jesus looked up and said, “Father, I thank you that you have heard me. 42 I knew that you always hear me, but I said this for the benefit of the people standing here, that they may believe that you sent me.”
Lazurus' 'death' was for the glory of God that those who saw his resurrection would believe.
What was the point, if at death all is decided already?
Jesus is the Resurrection and the Life He alone defeated death.
Further scripture informs us:
Hebrews 9:
26 Otherwise Christ would have had to suffer many times since the creation of the world. But he has appeared once for all at the culmination of the ages to do away with sin by the sacrifice of himself. 27 Just as people are destined to die once, and after that to face judgment, 28 so Christ was sacrificed once to take away the sins of many; and he will appear a second time, not to bear sin, but to bring salvation to those who are waiting for him.
My bold. No, prayer for the dead is useless, pray for the living for their conversion, as the dead are judged at death rendering prayer ineffective since if condemned it avails nothing and if saved adds nothing. If there was 'another' way, would not our Savior have told us? To believe otherwise is Gnosticism.