When you say "The Great Commission," all good Protestants know what you are talking about: Matthew 28:19-20 .
Everyone takes this as an active call to go make converts [though clearly that is not the point... Jesus tells people to make disciples and to teach people to obey everything He has commanded, which fits well into the view of salvation shown in the Later Prophets, but Christians have never been very good about letting those passages encroach on their doctrine...perhaps if Paul had written Ezekiel and Malachi the would be read more...] but I digress, I think it is important to look at the non-evangelistic side of this responsibility.
Consider Matthew 5:19 and Luke 17:2 [which may or may not be referring to believers], and then consider Luke 12:42-47
Luke 12:42-47 is an interesting parable describing a steward left in charge of a household. The master comes back and finds people not doing his will. Jesus describes 3 classes of people. The steward in charge is both killed and "assigned a lot with the unbelievers." Those who knew what they should be doing but were not doing it were punished severely while those who did not know what they were supposed to be doing [and hence were not doing it] are given few lashes.
At the time of Jesus' telling the parable, He is referring to the priests who had failed in teaching the Jews how to please God. That aspect of the parable is clear. [Most of the middle chapters of Luke deal with attacking the leaders of the Jews who had failed in their roles as shepherds.]
What is unclear are the eschatological implications [what does it mean to have a light beating? How does a severe beating differ from being assigned a lot with the unfaithful...which for the Jews would mean being cast out of the covenant...]
It's not surprising that the eschatological implications are unclear, the Jews have never had a clear understanding or prescription of the afterlife. There is almost nothing about the afterlife in the entire Old Testament, and even though Daniel 12:2 describes a resurrection the idea really didn't take hold in Jewish culture until the intertestamental time.
What is more concerning and important is the application of this passage to Christians today, assuming there is some application. Given that God has removed the barrier between Jews and Gentiles and subordinated all of Creation to Christ's rule, we must think of all men [including those who do not believe or have never known of Christ] as being "in the household.' Jesus is, after all, the propitiation for the entire world [1st John 2:2] and savior of all ("especially those who believe") [1st Timothy 4:10], so it is best to think of all people as in God's nation....just some do not know who their King is.
But if that is the case, and Christians are instructed to show others how to please God, as the great commission indicates, what ramifications does that have for us when our actions drive people away from Christ or following Christ's teachings? Christians need to take very seriously the effects we have when we are not "spreading the Gospel."
If verses like Ezekiel 3:18 [one of many verses that say the same thing] are any judge, if we fail to adequately warn people of the need to repent [one of the most common teachings in acts] and indeed cause them to "stumble" by turning them off due to our stereotypical judgmentalism and hypocrisy, there could well be a reckoning. After all, recall Jesus' warnings to His own disciples in Mark 9:50 [people would do well to note that the entire passage in Mark is told only to the disciples]