1 John 5:16

If any one see his brother sinning a sin, not to death, let him ask, and he will grant to him life, for those who sin not to death. There is a sin leading to death. I do not say concerning it, that you should ask.

Revelation 2:11

Whoever has an ear, let him hear what the Spirit says to the congregations. The conqueror shall not be injured by the second death.

Revelation 20:6

Happy and holy is he who has a part in the first resurrection! on such, the second death shall have no power; but they shall be the priests of God, and of Christ: and they shall reign with him a thousand years.

Revelation 20:14

And death and hades were cast into the lake of fire: this is the second death.

Revelation 21:8

But, as for the cowards, and unbelieving, and the abominable, and murderers, and prostitutes, and sorcerers, and idolaters, and all liars-their part shall be in the lake which burns with fire and brimstone, which is the second death.

Treasury of Scripture Knowledge

Summary

But of the tree of the knowledge of good and evil, thou shalt not eat of it: for in the day that thou eatest thereof thou shalt surely die.

Bible References

Surely

1 John 5:16
If any one see his brother sinning a sin, not to death, let him ask, and he will grant to him life, for those who sin not to death. There is a sin leading to death. I do not say concerning it, that you should ask.
Revelation 2:11
Whoever has an ear, let him hear what the Spirit says to the congregations. The conqueror shall not be injured by the second death.
Revelation 20:6
Happy and holy is he who has a part in the first resurrection! on such, the second death shall have no power; but they shall be the priests of God, and of Christ: and they shall reign with him a thousand years.
Revelation 21:8
But, as for the cowards, and unbelieving, and the abominable, and murderers, and prostitutes, and sorcerers, and idolaters, and all liars-their part shall be in the lake which burns with fire and brimstone, which is the second death.