"I'm pretty confident that the majority of people, religious or not, would argue that they know how to Love and that they show their love for people on a daily basis."
There is a kind of love, though, that people don't know how to do and don't show on a daily basis, that Jesus particularly associated with being born of God (Matthew 5:43-46, ESV quoted):
“You have heard that it was said, ‘You shall love your neighbor and hate your enemy.’ But I say to you, Love your enemies and pray for those who persecute you, so that you may be sons of your Father who is in heaven. For he makes his sun rise on the evil and on the good, and sends rain on the just and on the unjust. For if you love those who love you, what reward do you have? Do not even the tax collectors do the same?
This kind of love isn't easy: while it's natural to love friends, and while there are charitable people who are willing to love strangers, it's very rare that a person will be willing to love enemies—people let hate come first, and if there's hatred it tends to preclude love. But this is not the example God has set for us with his own love (Romans 5:8):
But God shows his love for us in that while we were still sinners, Christ died for us.
God's love led him to die for us 'while we were enemies' (v. 10).
There is a clear reason that this kind of love is necessary to being a truly loving person, though I'm not aware of any place the Bible itself makes it explicit; an example of the reasoning is given by Lao Tzu in the Tao Te Ching (49):
Those who are good I treat with goodness;
Those who are not good I also treat with goodness —
Virtue is goodness.
Just as being good to people means being good to people, regardless of anything else, being loving means being loving, regardless of anything else.