What does “all” mean in Romans 6:10?
Answer: Jesus died with reference to sin once for "all time".
When faced with such an ambiguity, we look to other translation and similar verses for clarification.
The word [time] inserted in the ESV verse by me. The word "time" is implied in the verse and the translators could have added the word for clarification. The Christian Standard Bible, The World English Bible, and The Aramaic Bible have added the word "time" in the verse.
Romans 6:10 ESV
10 For the death he died he died to sin, once for all**[time],** but
the life he lives he lives to God.
Christian Standard Bible
For the death he died, he died to sin once for all time; but the life
he lives, he lives to God.
World English Bible
For the death that he died, he died to sin one time; but the life that
he lives, he lives to God.
Aramaic Bible in Plain English
For he who died to sin, died one time, and because he lives, he is
living to God.10 "For the death that he died, he died to sin one time;
but the life that he lives, he lives to God."
Other similar verses help us clarify the ambiguity.
Hebrews 9:28 (ESV)
28 So Christ, having been offered once to bear the sins of many, will
appear a second time, not to deal with sin but to save those who are
eagerly waiting for him.
1 Peter 3:18 (ESV)
18 For Christ also suffered once for sins, the righteous for the
unrighteous, that he might bring us to God, being put to death in the
flesh but made alive in the spirit,