Nor is there need for food, gold, etc.
Yet they're there.
Yes. Even Jesus himself said he would drink wine in the afterlife.
In heaven, there will be no separation from God. There will be no need to eat, sleep, have the desire for sex, etc. We will be worshiping Jesus with the multitude of believers.
Marriage was created by God. It is a representation of the Bride of Christ and the Bridegroom. When a married couple have sex, they are physically united and two become one flesh. In the new heaven and new earth, marriage and sex (as great as they can be for married couples), it is really not the same as what full closeness (whatever the opposite of total separation from Christ is) with God will be like.
When Jesus was preaching about the 7 husbands? That's the gospel that everyone refers to. However, Jesus did NOT explicitly state there would be no sex in heaven.
There is a strong case for sex in heaven. There is also a strong case against it.
1. The LORD's prayer itself. "Thy will be done on earth as it is in heaven."
2. God himself did not make us eunuchs.
3. God himself designed sex, pleasure, our organs, etc.
4. We are made in the image of GOD. GOD himself even said "Let us make man in our image, after our likeness."
5. Jesus himself said he would enjoy wine in heaven, which IS at least one example of an earthly pleasure that will carry on in heaven.
6. Psalm 84:11 "No good thing will be withheld from them that walk uprightly."
7. 1 Cor 7:5 ->"Do not deprive one another except with consent for a time, that you may give yourselves to fasting and prayer; and come together again so that Satan does not tempt you because of your lack of self-control."
8. Pastor and missionary Jonathan Edwards (1703-58): “[In heaven] the glorified spiritual bodies of the saints shall be filled with pleasures of the most exquisite kind that such refined bodies are capable of….The sweetness and pleasure that shall be in the mind, shall put the spirits of the body into such a motion as shall cause a sweet sensation throughout the body, infinitely excelling any sensual pleasure here” (Jonathan Edwards, Miscellany 233: Yale Works, 13:351).
9. A lot of people think of sex as rebelling against GOD because it's so often associated with sin. GOD designed it to be part of HIS plan and actually needed it for HIS plan.
10. Since GOD made sex, does GOD unmake it?
11. Psalm 23:1 "The LORD is my shepherd. I shall not want." Shall not want spells it out pretty clearly.
12. I think we will still need relationships. People will genuinely want to be with their friends and families. Philippians 4:19 "And my GOD will supply all your needs according to His glorious riches in Christ Jesus."
13. Psalm 34:9 "Fear the LORD, you His saints, for those who fear Him lack nothing.
14. Psalm 34:10 "Young lions go lacking and hungry, but those who seek the LORD lack no good thing."