Some teach that those who die without accepting Christ will have a second chance to do so after death (or when He returns, or on Judgment Day). As with any false teaching, if we can provide even one single clear and unambiguous verse that contradicts the teaching, then you can see that it is indeed a false teaching. So, I present:
And inasmuch as it is appointed for men to die once and after this comes judgment. – Hebrews 9:27
Scripture is clear that the state of your spirit/soul is fixed at your death for all eternity, with no second chance at redemption – in sin if you die without Christ, or in righteousness if you die in Christ. See the Beyond the Tomb book for more information about your eternal soul and what happens after death.