When you ask believers what is faith, most of the answers I hear explain a Christian's faith, such as "Faith is trusting in Christ", "Faith is receiving God's gift of salvation". While those statements are true, they are specifically related to the faith of a Christian, those statements do not define faith at it's base. Fortunately the writer of Hebrews lays out the answer to this question of what is faith plainly in Hebrews 11:1.

Now faith is the assurance of things hoped for, the conviction of things not seen. - Hebrews 11:1

There it is, your exact and full, from God, definition of what faith is. Notice Christ is not mentioned in this definition. Don't get me wrong, faith in Christ is of utmost importance and is the difference between being saved and not. The author here is giving a definition of faith at it's element, trust, it is placing that faith in Christ that God credits to us salvation (Rom. 4:3, Gal. 3:6).

So look closely at Hebrews 11:1 definition of faith. Could that definition be applied to non-believers? Yes it could. Think about it. Do not all men have assurance of things hoped for and conviction of things not seen? I'm going to be a bit extreme here but don't believers and non-believers alike feel assured that gravity won't suddenly stop working? Nobody has 100% proof that it won't but yet I can honestly say I've never come across a man that had preparations ready in the event that gravity ceases to stop pulling them down. Such a person then trusts in gravity.

A less extreme example would be when we eat. Do we not have assurance that the food we eat is not poisoned or else why would we eat it? Yet we eat with conviction that our food hasn't been poisoned. (I know some of you are thinking of extreme examples of people who are unreasonably paranoid and go through abnormal measures to guard against people doing malicious things with their food, I guess we could say of them that such a person has "lost faith in humanity".)

What I'm getting at is all men have faith as defined in Hebrews 11:1, that does not mean that all men have faith in Jesus. Those that have their faith appropriately in God do (Gen. 22:8, Rom. 10:9), while those like the demons who have their faith inappropriately (James 2:19-20) do not. Abraham exhibited his faith in God prior to Christ's coming and still it was credited to him as righteousness (Gen. 15:6). On the contrary, Jesus rebuked the Jews for misplacing their faith in such is in Abraham (John 8:39, Matt. 3:9), their lineage (John 8:41, cf Rom 9:8), works (cf Rom. 2:17-29), and even in scripture, thinking scripture itself was the source of life, when in fact scripture was testifying of Christ being the source of life.

³⁹ You search the Scriptures because you think that in them you have eternal life; it is these that testify about Me; 40 and you are unwilling to come to Me so that you may have life. - John 5:39-40

Be it wrong, these men had "assurance of things hoped for". They had assurance (faith) that scripture would impart to them life, just like others had faith in their lineage and in their performance, but as it is here that is misplaced faith and therefore not leading to salvation. Why? Because the object of their faith was not actually able to accomplish it, not their lineage, not their works, and not even scripture. They chose to place their faith in scripture itself instead of heeding scripture and it's testimony of Jesus.

Even atheist have faith. In fact, many would say it takes more faith to be an atheist than a Christian as the evidence when looked at truthfully is stacked against them. I know I'm opening a door to another debate here but what I'm getting at is, listen to an atheist and you will see at the root of their belief system is an object unseen given them assurance, beit morbid, that they won't have accountability for their unloving actions here on earth. They have assurance that it does not matter what they do because though they don't see it, they believe there is no afterlife. On a side note, I would argue they are choosing this (Rom. 1:20) because it's what they want (John 3:19).

Faith that leads to salvation is one that trusts in God. Scripture says "Abraham believed God", it does not merely say "Abraham believed". (Though if it had we would know it was God in whom He believed (Gen. 15:5-6, Gen. 22:8).) Saving faith takes God at His word (Gen. 15:5-6). Believing in God is synonymous with receiving Christ (John 1:12, 5:43-44) resulting in salvation. Notice in John 5:40 above where it states these men were "unwilling" to come, not unable. They had the ability to come to Christ (Acts 17:30) but deliberately were choosing not to. It's not that they don't have the ability to have faith, but are unwilling to align themselves with Jesus. Much like Romans 1:18-20 which states that men, though clearly perceiving the things of God and without excuse having a knowledge of God and His attributes, choose not to trust or receive Him but instead suppress the truth. Likewise these men chose to trust in scripture, to trust in knowledge (1 Cor 1:22-23), and not in Jesus. Like these men we have faith, we have knowledge, but unlike these men we don't expect scripture to impart life but we trust in Jesus whom scripture testifies about. We've chosen not to suppress the truth but to receive it. That is the difference. Everyone has faith as Hebrews 11:1 defines, but for various reasons not all are willing to put that faith in Jesus.

Faith in and of itself has no value, no merit. The value of faith is in it's object. If faith saved then it wouldn't matter what your faith is in. But as we've explored here, it's not having faith (void of proper placement) that saves, but rather what your faith is in that matters and as Christians we know that to be Jesus Christ! This is why a mustard seed of faith can move mountains (Luke 17:5-6, Matt. 17:20). Not because our faith is powerful, but because a mustard seed of faith, be it small, still genuinely trusts in Christ who is powerful!