23That same day the Sadducees, who say there is no resurrection, came to him with a question.24"Teacher," they said, "Moses told us that if a man dies without having children, his brother must marry the widow and have children for him. 25Now there were seven brothers among us. The first one married and died, and since he had no children, he left his wife to his brother.26The same thing happened to the second and third brother, right on down to the seventh.27Finally, the woman died. 28Now then, at the resurrection, whose wife will she be of the seven, since all of them were married to her?"
29Jesus replied, "You are in error because you do not know the Scriptures or the power of God.30At the resurrection people will neither marry nor be given in marriage; they will be like the angels in heaven. 31But about the resurrection of the dead—have you not read what God said to you, 32'I am the God of Abraham, the God of Isaac, and the God of Jacob'? He is not the God of the dead but of the living." 33When the crowds heard this, they were astonished at his teaching.
Notice that the Sadducees don't ask what the relationship between the woman and her seven husbands will be in Heaven, after their death. No, they are clearly referring to a future, physical resurrection, not an intermediate state. Though we know the Sadducees didn't really believe in the resurrection, the way they pose the question informs us about what those who did affirm resurrection believed. It doesn't indicate any sense of conscious existence before the resurrection.
The most compelling point is made by Jesus. When he says,"He is not the God of the dead, but of the living," it is a direct reference to resurrection. He isn't saying, "Abraham, Isaac and Jacob are alive in some spiritual place, conscious of their surroundings...therefore they are 'alive'". Instead, the basis for declaring them "alive" is clearly their future status in the resurrection.
I've referred to Jairus' daughter and Lazarus in my post on Easter, but because the post was focusing on Christ's resurrection, I didn't plunge into the Annihilation/Conditional Immortality subject once again. However, we must consider how Jesus spoke about death and life. In the gospels, besides raising himself, he only raises three other people; Jairus' daughter, Lazarus, and the son of a widow. In the case of Jairus' daughter and Lazarus, he describes them as being asleep. Especially in the case of Jairus' daughter, Jesus is adamant over the use of the term, telling the mourners that she is not dead, simply asleep. It's repeated in Matthew, Mark, and Luke in much the same way.
23When Jesus entered the ruler's house and saw the flute players and the noisy crowd, 24he said, "Go away. The girl is not dead but asleep." But they laughed at him. 25After the crowd had been put outside, he went in and took the girl by the hand, and she got up.
and about Lazarus:
11After he had said this, he went on to tell them, "Our friend Lazarus has fallen asleep; but I am going there to wake him up."
In raising the dead man in Luke, he doesn't refer to him as being asleep, but he does raise him by directly addressing his body.
12As he approached the town gate, a dead person was being carried out—the only son of his mother, and she was a widow. And a large crowd from the town was with her.13When the Lord saw her, his heart went out to her and he said, "Don't cry."
14Then he went up and touched the coffin, and those carrying it stood still. He said, "Young man, I say to you, get up!" 15The dead man sat up and began to talk, and Jesus gave him back to his mother.
Acts 7:59-6059While they were stoning him, Stephen prayed, "Lord Jesus, receive my spirit." 60Then he fell on his knees and cried out, "Lord, do not hold this sin against them." When he had said this, he fell asleep.
36"For when David had served God's purpose in his own generation, he fell asleep; he was buried with his fathers and his body decayed. 37But the one whom God raised from the dead did not see decay.