Thank you for your inquiry regarding verses that are present in other versions of the Bible but are missing from the English Standard Version. Please be assured that we take all such inquiries very seriously, as it is our desire to faithfully translate God's Word from the original Bible languages into English.
As you may have noticed, there is usually a footnote attached to such verses, explaining why they were omitted as well as quoting the text of the omitted verses.
Such passages have been omitted from the ESV because, in the judgment of the ESV translators, the most reliable Greek manuscripts did not include them. As you are probably aware, many very reliable ancient manuscripts have been uncovered. While none of these more recently discovered manuscripts call into question any major doctrine of Scripture, they do often provide helpful insights concerning the Bible text.
One thing that recent research into the Bible text has shown is that, as scribes faithfully copied passages of Scripture before the days of mechanical printing, they would sometimes insert marginal words or phrases that they intended as clarifications of the actual Bible text. Through the centuries, some of these “clarifications” were mistakenly thought to be part of the actual Bible text. The discovery of earlier manuscripts has helped biblical language scholars pinpoint many of these scribal additions.
You will find that almost all of the more recent Bible translations, including the ESV, agree as to where these scribal additions occurred.
Thank you again for your inquiry.