Hebrews 11:1:
"Now faith is the assurance of things hoped for, the conviction of things not seen." (ESV)
"Now faith is confidence in what we hope for and assurance about what we do not see." (NIV)
"Now faith is being sure of what we hope for, being convinced of what we do not see." (NET)
"Now faith is the certainty of things hoped for, a proof of things not seen." (NASB)
"Now faith is the realization of what is hoped for, the proof of things not seen." (LEB)
"Now faith is the substance of what is hoped for, the evidence of what is not seen." (KJV)
"Now faith is the reality of what is hoped for, the proof of what is not seen." (CSB)
"Now faith is the ὑπόστασις/hypostasis of what is hoped for, the ἔλεγχος/elenchos of what is not seen." (Greek/Greek transliteration)
1. I'm no biblical scholar let alone a Hebrews scholar. I'm just a simple layperson sharing what (little) I've learned about Heb 11:1 in a brief personal and devotional "study" I did earlier this morning. So please feel free to correct me.
2. The words I've bolded in Heb 11:1 seem to have been translated in either a subjective or an objective fashion.
a. The subjective seems to emphasize the person who has faith's state of mind. Their psychological state. Their "assurance", "confidence", or "conviction" in what is hoped for and what is unseen.
b. By contrast, the objective seems to emphasize the objective reality of what is hoped for and what is unseen. In this respect, "faith" seizes upon a solid object that can't be seen at the present time but will be seen in the future.
By the way, in context, what is hoped for and what is unseen seem to be about time rather than space, though perhaps it's both. That is, what is hoped for and what is unseen seem to point to the future, to eschatological fulfillment, not to the spiritual realm, per se. Although of course we Christians believe there is an unseen spiritual realm (e.g. 2 Kgs 6:17).
3. Looking at the two Greek words:
a. ὑπόστασις/hypostasis. Cf. Heb 1:3 about Christ's "nature": "He is the radiance of the glory of God and the exact imprint of his nature [hypostaseos]" (ESV). I presume there are good arguments for the subjective emphasis in translation, but I don't know what they would be. My reason for thinking the objective emphasis is the better translation is the example of "the people of old" "commended" for their faith in Heb 11. They seem to be illustrative examples of faith, of Heb 11:1. It seems to me they thought of faith in an objective reality (at least that's where the emphasis would seem best tilted), not faith in a subjective state of mind which would seem to come close to saying faith in faith. But perhaps a combination of the subjective and objective with a stronger degree of emphasis on the objective would be a reasonable translation? Say something like this: "Now faith is being sure of the reality of what is hoped for...".
b. ἔλεγχος/elenchos. As I understand it, elenchos has reference to demonstrating something is true or someone passes muster after detailed cross-examination. Interestingly, the Socratic method or Socratic debate is also known as "elenctic" debate. The idea seems to be scrutiny or cross-examination of someone or something to see if they or it is true or false, proven or disproven, accurate or inaccurate. So "elenchos" in Heb 11:1 seems to be saying that "what is not seen" has been proven to be true after examination or scrutiny. What may have once been debatable or disputable has emerged demonstrably proven.
c. Perhaps a reasonable translation of Heb 11:1 could be: "Now faith is being sure of the reality of what is hoped for, proof after examination of what is not seen."
4. It's interesting that Heb 11:1 defines faith as the direct opposite of what militant atheists typically think faith is. Militant atheists say faith is blind faith. A leap of faith. A leap into the dark or unknown. Faith without reason or evidence. Faith based primarily or solely on emotions or feelings.
However, Heb 11:1 contradicts these notions of faith. Heb 11:1 teaches that faith is trust in an objective reality. An objective reality that we can't see at present, but nevertheless it is an objective reality based on demonstrably proving its truth in light of intense examination. A subjective feeling or emotion like assurance or conviction comes after the fact and in light of having demonstrated the reality of faith's object.
This is another piece of evidence that Christianity has always been an apologetic faith: we defend our faith, we examine our faith, we prove our faith, etc.