James 4:17

So any person who knows what is right to do but does not do it, to him it is sin.

John 9:41

Jesus said to them, “If you were blind [to spiritual things], you would have no sin [and would not be blamed for your unbelief]; but since you claim to have [spiritual] sight, [you have no excuse so] your sin and guilt remain.

Luke 12:47-48

And that servant who knew his master’s will, and yet did not get ready or act in accord with his will, will be beaten with many lashes [of the whip],

John 13:17

If you know these things, you are blessed [happy and favored by God] if you put them into practice [and faithfully do them].

John 15:22

If I had not come and spoken to them, they would not have [the guilt of their] sin; but now they have no excuse for their sin.

Romans 1:20-21

For ever since the creation of the world His invisible attributes, His eternal power and divine nature, have been clearly seen, being understood through His workmanship [all His creation, the wonderful things that He has made], so that they [who fail to believe and trust in Him] are without excuse and without defense.

Romans 1:32

Although they know God’s righteous decree and His judgment, that those who do such things deserve death, yet they not only do them, but they even [enthusiastically] approve and tolerate others who practice them.

Romans 2:17-23

But if you bear the name “Jew” and rely on the Law [for your salvation] and boast in [your special relationship to] God,

Romans 7:13

Did that which is good [the Law], then become death to me? Certainly not! But sin, in order that it might be revealed as sin, was producing death in me by [using] this good thing [as a weapon], so that through the commandment sin would become exceedingly sinful.

2 Peter 2:21

For it would have been better for them not to have [personally] known the way of righteousness, than to have known it and then to have turned back from the holy commandment [verbally] handed on to them.

Treasury of Scripture Knowledge

Summary

Therefore to him that knoweth to do good, and doeth it not, to him it is sin.

Bible References

General references

Luke 12:47
And that servant who knew his master’s will, and yet did not get ready or act in accord with his will, will be beaten with many lashes [of the whip],
John 9:41
Jesus said to them, “If you were blind [to spiritual things], you would have no sin [and would not be blamed for your unbelief]; but since you claim to have [spiritual] sight, [you have no excuse so] your sin and guilt remain.
John 13:17
If you know these things, you are blessed [happy and favored by God] if you put them into practice [and faithfully do them].
John 15:22
If I had not come and spoken to them, they would not have [the guilt of their] sin; but now they have no excuse for their sin.
Romans 1:20
For ever since the creation of the world His invisible attributes, His eternal power and divine nature, have been clearly seen, being understood through His workmanship [all His creation, the wonderful things that He has made], so that they [who fail to believe and trust in Him] are without excuse and without defense.
Romans 2:17
But if you bear the name “Jew” and rely on the Law [for your salvation] and boast in [your special relationship to] God,
Romans 7:13
Did that which is good [the Law], then become death to me? Certainly not! But sin, in order that it might be revealed as sin, was producing death in me by [using] this good thing [as a weapon], so that through the commandment sin would become exceedingly sinful.