The english word ‘love’ gets a lot of unmerited airtime in our bible translations. Mostly when we read ‘love’ in an english bible something significantly different is meant by the author. Love is a catchall word we use to mean a lot of things and its roots are neither Greek nor Hebrew. It’s a Swiss Army Knife english word that covers a range of priorities, choices, emotions, and chemical reactions we experience, but it is actually extremely shallow.
The 1977 Bee Gees song ‘How Deep Is Your Love?’ highlights the problem. It’s a question that can be asked a couple ways: "How much do you love me?" or "To what extent do you love me?" or "For how long will you love me?" or "Under what conditions will you stop loving me?" The song asks something humans always ask each other, "what is your definition of love?" as if love is a subjective thing. We ask these questions because love is exactly a subjective thing. 
We love, then we stop loving; our tastes and desires change; we use the same word to describe how we feel toward a toasted cheese sandwich, God, and our spouse. We explain to our partners, as we break up with them, that we no longer 'feel love' for them. It’s as if love evaporates if it is no longer felt, and that’s about right. It is a weak and dependent word. We’re in it, then we’re out of it. It’s entirely based on feelings, and it goes about as deep as affection, to answer the Bee Gees.

We ask these questions because love is exactly a subjective thing. 
 You see ‘love' is an English word. It has Indo-European and Sanskrit roots.; it does not come to us from Greek or from Hebrew. It’s definition is very narrow and subjective, it is shallow. And yet it is, in our English bibles, a central biblical concept, it may even be the central biblical concept. God is defined as “love" (1 John 4:8&16). Does that mean that God loves only as much as He feels it? Does it mean His love can sometimes be passionate and strong, and at other times it can evaporate depending on how He feels? Is He in love sometimes and then falls out of love at other times?
When we read “God is love” we end up thinking of him as one of two wild definitions. He is either 'The Godfather', who hates everyone outside His dysfunctional Family, or He is 'Sugar Daddy', who gives provision in exchange for fulfilling his perverted desires. Neither of those are what is meant by biblical love.
 
Some people equate love with devotion and commitment, but not everyone does, I’d say actually precious few do. We have vastly differing definitions for what is arguably the foundational human necessity. This is why the Bee Gees’ question is so relatable. "You say you love me," "but how deep is your love?"
The Beetles suggested, rather emphatically, that “all you need is love”, but Haddaway asked, "what is love?” And Tina Turner called love, "a second-hand emotion”, and asked, “who needs a heart when a heart can be broken?” Dave Matthews weighed in with, “tonight let’s be lovers and tomorrow go back to being friends, tomorrow say goodbye." Love is such a fickle thing!
This is the word we have chosen to describe the essence of The Eternal Creator, is it any wonder the world is confused about God?
 
The translation problem comes in two parts:
  1. Firstly we have one English word for multiple original language words, each with very little association with another.
    To see this problem imagine asking a grocery store clerk for assistance finding the corn flakes using only the word ‘box’ to describe breakfast, cereal, grains, corn flakes, Kelloggs, bowl, milk, morning, food, and eat.
    Between just two people, is not difficult to imagine that they'd eventually figure it out, but surely the store clerk would wonder why you didn't just use the right word. In the case of the word ‘love', however, we're dealing with a single word which has been accepted by billions of people, and entrenched over an extremely long time, and doing an exceptionally poor job describing one of the core tenants of not only our faith but also our humanity. We have put a chimp on the throne.
  2. Secondly we have been taught to think that there are three or four kinds of ‘love' in the New Testament. As if when we see the word ‘love’ we should ask, “which type of love is this?” 
    Greek readers were not thinking that agapē, eros, and phileō were each a type of love. They are independent concepts in greek, especially agapē; it is unlike anything and is certainly not a type of something else. Love is a poor english substitute we have chosen for disparate ideas, it is not a category of greek words.
The word ‘love' comes from a Proto-Indo-European root ‘leubh-' meaning to care, or to desire. A lot of concepts are founded on it, you can hear the origins come through when you say these words: belief; furlough; leave (as a noun); libido.
In Sanskrit we find the word ‘lubhyati' which means 'desires' and ‘lobhaya’, which is is 'to make crazy'. 
We also see it migrating into Latin with ‘lubet’, and later ‘libet’, which mean 'pleases'. We also see ‘libido', or ‘lubido’ which mean 'desire', 'longing'; 'sensual passion', or 'lust'.
In Old English we find ‘lufu’ which means 'feeling of love'; 'romantic sexual attraction'.
So the Bee Gees’ question is entirely appropriate, How deep is your love? I really need to know because the word itself is pretty shallow. It does not even begin to describe what humans actually need from each other (and to give to each other). 
The first commandment is “You shall love the LORD your God with all your heart and with all your soul and with all your might.” (Deut 6:5)
The very command demands considerably more than the word love is able to give.

There are 2 English words that I believe define agapē somewhat accurately, at least a lot more accurately than love
Most times we read of ‘love’ in the new testament it is a Greek word: agapē. There are 2 English words that I believe define agapē somewhat accurately, at least a lot more accurately than love:
Devotion and Commitment
I hear people argue for sex outside of a marriage commitment from 1 Corinthians 13, “it’s only love, right?” they say. Or, “sex is just a kind of love, like in Corinthians.” 
It's completely true that 'lust' has its roots in English word 'love'. It's also true that its Greek equivalent is ‘eros’. But those ideas have absolutely nothing to do with agapē, which we find in 1 Corinthians 13. They are not two kinds of the same basic thing, not at all!
 
If we replace ‘love’ with 'devotion' and 'commitment' we begin to grasp a little of what the authors meant and what they didn’t mean: 
1 Corinthians 13:4-8Perfect Commitment is patient, kind, does not envy or boast, is not proud or self-seeking, does not ridicule, it is slow to anger, keeps no record of wrongs, does not delight in evil, rejoices in truth, always protects, trusts, hopes, perseveres. Perfect Commitment and complete Devotion never fail.” 
In other words we need more than mere ‘love’. Saying "I love you" is hardly the same as a promise of complete devotion and commitment. Sex, as wonderful as it is, is neither commitment nor devotion.

If we replace ‘love’ with 'devotion' and 'commitment' we begin to grasp a little of what the authors meant and what they didn’t mean
The same is true when we remove the weak ‘love' from Jesus discussion with Peter at the end of John. Jesus uses two very different words here, as He confronts, forgives, and reinstates Peter after Peter’s spectacular display of abandonment John 21:15-17:
Jesus: “Peter are you committed to me more than anyone else? (agapē)” 
Peter: “Yes Lord.” 
Jesus: “Peter are you perfectly devoted to me? (agapē)
Peter: “Yes Lord.
Jesus: “Peter are you even my friend? (phileō)
In that moment Peter was finally and fully face-to-face with exactly how fickle, shallow, and selfish he actually was. He admitted: “I don’t know Lord, I was so sure of myself; but I believe that you, and you alone, know if I’m even your friend.
Jesus: “That is enough for now, Peter, and enough to see you through to your end. For now I want you to provide, like a shepherd, for my people.
 
At best 'love' is merely 'affection'. Commitment is absolute, devotion is complete. No one needs to ask how deep commitment is, or how deep devotion is. If they are not complete then they are not present. Perhaps, if we read it this way we may begin to behave as Jesus commanded in John 13:34-35 "34 A new commandment I give to you, that you commit to one another: just as I have committed you, so you also are to be devoted to one another. 35 By this all people will know that you are my disciples, if you have complete devotion and commitment for one another.

No one needs to ask how deep commitment is, or how deep devotion is. If they are not complete then they are not present.