Without a doubt, the Bible does teach at least two resurrections. The first one is of the righteous at the Second Coming of Jesus Christ (1Thessalonians 4:16) where they will be made alive and composed of the same substance as he is (1Corinthians 15:42 - 54). A second raising of the dead will also occur after the 1,000-year reign (the Millennium) of Christ on the earth. This raising is for all those who never have a full chance at hearing or understanding the gospel message (Revelation 20:5).
There is also some scriptural evidence suggesting a third and final resurrection. Its purpose would be to resurrect those who willfully, and with full knowledge, reject God and what he stands for (they committed the unpardonable sin) and they refuse to repent (Daniel 12:2).
The first two
No single passage in the Bible clearly shows all the resurrections that will be performed. There are some sections, however, that do discuss two of them. A passage in Revelation 20 is one such of these sections.
"And I saw thrones; and they that sat upon them, and judgment was given to them; and I saw the souls of those who had been beheaded for the testimony of Jesus, and for the Word of God, and those who did not worship the beast, or his image, and did not receive the mark in their foreheads or in their hands; and they lived and reigned with Christ a thousand years. (But the rest of the dead did not live again until the thousand years were completed). This is the first resurrection" (Revelation 20:4 - 5)
Jesus collaborates the above in John 5:28 - 29.
The apostle Paul states that a raising of the dead takes place at Christ's Second Coming. This is the first resurrection of the dead in God's great plan for all mankind (1Corinthians 15:51 - 52).
The second one
The second resurrection (also known as God's white throne judgment) occurs after Jesus' Millennial rule (Revelation 20:11 - 13). It is the bringing back to physical life the billions who died, before Jesus' return, who never received a FULL opportunity to understand God's truth. Ezekiel's strange vision of an incredible number of dry bones (Ezekiel 37) discusses this momentous raising of the dead. In vision, the prophet is standing in a valley containing the remains of countless humans and is asked, by God, if these people can live again (verse 3). The Eternal answers his own question and declares that they will!
5. Thus says the Lord GOD to these bones, "Behold, I will cause breath to enter into you, and you shall live. 6. And I will lay sinews on you, and will bring up flesh on you, and cover you with skin, and put breath in you, and you shall live. And you shall know that I am the LORD . . ."
13. "And you shall know that I am the LORD when I have opened your graves, O My people, and have brought you up out of your graves. 14. And I shall put My Spirit in you, and you shall live, and I will place you in your own land. And you shall know that I the LORD have spoken it and have done it," says the LORD (Ezekiel 37:5 - 6, 13 - 14, HBFV)
All those in this resurrection will finally have their minds opened and given a chance to repent so that they can receive God's spirit. They will have to, as all those who came before them, live a physical life of overcoming and building righteous character (possibly lasting for one hundred years - see Isaiah 65:20). Those who God deems worthy of salvation will have their names written in the book of life (Revelation 20:13, 21:27) and be given the gift of living forever.
A possible final resurrection
There exists one final group of people that must be taken care of before God creates a brand new earth and universe (Isaiah 65:17, Revelation 21:1). This group is composed of all those humans who have committed the unpardonable sin. They, at one time, understood the truth but then knowingly and willfully rejected it (Matthew 12:32, Hebrews 6:4 - 6, 10:26 - 27, etc.). They hardened their hearts against the Eternal, refused to repent of their sins and, like the devil and his demons, have made him their enemy. Since they have become incorrigibly wicked, their fate is to be put completely and totally out of existence in a lake of fire (Revelation 20:15, 21:8).
The Bible is unclear as to when and how God will administer the death penalty to all those humans who reject him and his offer of salvation. One possibility is a distinct third resurrection that would occur one hundred years (Isaiah 65:20) after the second one. It would include all those who died, before the white throne judgement, who knowingly rejected the truth. These people, along with those still alive who became wicked after the second resurrection, would together be thrown into the lake of fire.
God could also take care of all the wicked people without performing a distinct resurrection. He, as part of the white throne judgement, could resurrect all those who have rejected him up to that point. Those deemed unrepentant and wicked, at that time, would receive the second death. Those who reject him during the hundred years after this event, since they have already experienced one physical death and resurrection (1Corinthians 15:21 - 22, Hebrews 9:27), would go straight to their destruction.