The most difficult part of the Greek window concerns the variants in the Greek text. Almost every Bible verse has one or two alternative text readings. We discuss an example to show you how you can use the manuscript information in the digital Study Bible to come to an assessment in your choice between a text and its variant reading (see also the article "The New Testament Text," and for how the manuscript information is listed, see the explanation at the Text Critical Device).
We take Matthew 18:15 as an example.
"But if your brother has sinned [against you], go and punish him in private.
The question we face is whether the words "against you" (demand se) were in the original or not. Indeed, this makes quite a difference to its explanation.

We pose a number of questions to the text, which are important for forming an opinion.
1.Which text is found in most manuscripts? This is stated by the edition H-F. This one does have the "against you.
2. What text do we find in the oldest manuscripts? For this you need to find the ages of the manuscripts mentioned after Byz, Eg and Ov via the index manuscripts look up. For our text, the oldest manuscripts are the Egyptian manuscripts 01 and 03, both from the 4th century. The manuscripts mentioned under Byz and Ov are from the 5th and 9th centuries. These oldest Egyptian witnesses lack the "against you.
3. What is the distribution of manuscripts of the text and variant reading? Byz, Eg and Ov largely coincides with a geographical designation. Indeed, it is argued, that the more scattered the manuscripts are, the more likely there is an original reading. The text with 'against you' is found in both Byz and Ov manuscripts. The reading without 'against you' we find only in manuscripts of the type Eg.
4. What has been the church text through the centuries? We find these under the attribute Byz. For those who believe in divine preservation of the text in the church over the centuries, this may be an argument. In our verse, the Byz manuscripts have a text with "against you.
5. What does modern text critical science choose to do? We find this one behind N25 and N26 or N27. This one is not unified in our verse. In N25 we chose the oldest Eg witness without "against you," but in N26 we have changed this and do render the "against you," albeit in text brackets, to indicate that this is not entirely certain.
6. What is the choice of modern translations? We see that about three translations have a text with "against you" (SV, HV and NIV) and eight translations have a text without "against you" (NBG, WV, GNB, NEB, NASB, RLU, REU and BJ). Often these data parallel the year of publication of the various Nestle editions, since most Bible translations had one of these editions as a starting point. So one should not attach too much independent value to this last finding. The translations are listed specifically to give you an insight into whether a particular difference is a translation difference or a text difference.

Conclusion
If we are now to make a judgment based on all the data collected, it depends in part on our positioning on two fronts. First, there is the theorizing related to historical data. For example, it is important to know to what extent the process of spreading and multiplication of manuscripts has been influenced by historical events, so that it is no longer a matter of a "normal" process and one cannot simply assume, for example, that most manuscripts lead to the most original reading. Much study is still needed in this area.
A second issue is that of internal and external proofs. The questions we just asked, the answers to which we could find in the second column of the Study Bible, all lie in the realm of external evidence. However, does one attach more value to internal arguments and individual readings, then the answers to the questions we posed are not sufficient to reach a final judgment. As for our verse, one can argue that the "against you" was an early addition, borrowed by an overwriter from verse 21, where it also occurs. However, one can also assume that the "against you" was deliberately omitted to generalize Jesus' statement. It may also have been done unconsciously by later transcribers, because in later Greek the pronunciation of the second part of hamartçsçi (sin) and eis se (against you) were the same. As you can see, it is very difficult to come to a judgment based on internal evidence alone. There are usually arguments for both positions.
At the end of this somewhat technical treatise, we would like to point out that all the variations in the manuscripts are limited to less than 1% of all the text. And of that small percentage, again, only a small portion is of doctrinal importance. So the reliability of the text of the NT, as handed down, is very close to 100%. True enough!