1 Corinthians 15:56

The [harmful] sting that causes [physical] death is sin [See Rom. 5:12]; and the power of sin [to do this] comes from the law. [See Rom. 8:2].

Romans 4:15

For the law brings [God's] wrath [i.e., because of man's failure to obey it perfectly], but where there is no law, there is no [responsibility for] sin.

John 8:21

Jesus again said to them, "I am going away and you will look for me, but you will die [condemned] in your sins. You cannot go where I am going."

John 8:24

Therefore I said to you that you will die [condemned] in your sins. For unless you believe that I am [the Messiah, who came from above. See verse 23], you will die [condemned] in your sins."

Romans 3:19-20

Now we [all] know that everything the law says applies to those who are under [obligation to obey] that law, [Note: Here "the law" appears to refer to the Old Testament Scriptures generally, since Psalms and Isaiah are quoted. See verses 10-18]. This is so that the mouth of every objector may be stopped [i.e., from making excuses for his sin], and thereby bring the entire world under God's judgment [i.e., both Jews and Gentiles].

Romans 5:12-13

Therefore, just as sin came into the world through [the action of] one man [i.e., Adam] and [physical] death through that sin, so [physical] death has spread to all people, because all people have sinned. [Note: This difficult passage (verses 12-21) seems to be saying that the entire human race must experience physical death because of Adam's sin (I Cor. 5:22), which is somehow considered to be everyone's sin. See Murray, pp. 180-187, for a thorough discussion].

Romans 5:15

But the free gift [of salvation through Christ] is not [exactly] like the sin [of Adam]. For if many people died [physically] because of the sin of the one man [i.e., Adam], how much more did God's favor abound by [providing] His gracious gift [of salvation] to many people because of the one man, Jesus Christ.

Romans 5:17

For if [physical] death ruled [over mankind] because of the sin of the one man [i.e., Adam], how much more will those who receive the abundance of God's unearned favor, and the gift of being right with Him, rule in [never ending] life through the one man, Jesus Christ.

Romans 5:20

Now the law of Moses was introduced [into the world] in order to cause sin to increase [i.e., it defined many things to be wrong that were previously not regarded as sin]. But with the increase of sin, God's unearned favor increased all the more.

Romans 6:23

For the wages for sinning is [spiritual] death, but God's free gift is never ending life in [fellowship with] Christ Jesus our Lord.

Romans 7:5-13

For when we were in the flesh [i.e., before conversion], our sinful desires, aroused by [the restrictions of] the law of Moses, worked in our bodies to produce activity that led to [spiritual] death.

Galatians 3:10-13

For all who seek to be right with God by trying to meet all the requirements of the law of Moses are under a curse [from God], because it is written [Deut. 27:26], "Every person is cursed [i.e., cut off from God] who does not continue to obey all of the requirements written in the law of Moses."

Hebrews 9:27

And just as it is destined for people to die one time, and [then] after that to be judged,

Treasury of Scripture Knowledge

Summary

The sting of death is sin; and the strength of sin is the law.

Bible References

Sting

John 8:21
Jesus again said to them, "I am going away and you will look for me, but you will die [condemned] in your sins. You cannot go where I am going."
Romans 5:15
But the free gift [of salvation through Christ] is not [exactly] like the sin [of Adam]. For if many people died [physically] because of the sin of the one man [i.e., Adam], how much more did God's favor abound by [providing] His gracious gift [of salvation] to many people because of the one man, Jesus Christ.
Romans 6:23
For the wages for sinning is [spiritual] death, but God's free gift is never ending life in [fellowship with] Christ Jesus our Lord.
Hebrews 9:27
And just as it is destined for people to die one time, and [then] after that to be judged,

The strength

Romans 3:19
Now we [all] know that everything the law says applies to those who are under [obligation to obey] that law, [Note: Here "the law" appears to refer to the Old Testament Scriptures generally, since Psalms and Isaiah are quoted. See verses 10-18]. This is so that the mouth of every objector may be stopped [i.e., from making excuses for his sin], and thereby bring the entire world under God's judgment [i.e., both Jews and Gentiles].
Romans 4:15
For the law brings [God's] wrath [i.e., because of man's failure to obey it perfectly], but where there is no law, there is no [responsibility for] sin.
Romans 5:13
For even before the law of Moses, sin was [being committed] in the world. But man is not responsible for [his] sin when there is no law.
Romans 7:5
For when we were in the flesh [i.e., before conversion], our sinful desires, aroused by [the restrictions of] the law of Moses, worked in our bodies to produce activity that led to [spiritual] death.
Galatians 3:10
For all who seek to be right with God by trying to meet all the requirements of the law of Moses are under a curse [from God], because it is written [Deut. 27:26], "Every person is cursed [i.e., cut off from God] who does not continue to obey all of the requirements written in the law of Moses."