And one of the scribes came up and heard them disputing with one another, and seeing that he answered them well, asked him, “Which commandment is the most important of all?”  Jesus answered, “The most important is, ‘Hear, O Israel: The Lord our God, the Lord is one.  And you shall love the Lord your God with all your heart and with all your soul and with all your mind and with all your strength.’  The second is this: ‘You shall love your neighbor as yourself.’ There is no other commandment greater than these.”

Mark 12:28-31 (ESV)

Love Is:
4a:  unselfish loyal and benevolent concern for the good of another: as
          (1):  the fatherly concern of God for humankind
          (2):  brotherly concern for others
     4b:  a person’s adoration of God

Definition of from Merriam Webster

So what does it mean to love God? Does it mean being at the church every time the doors are open? Does it mean accosting everyone you come across with the Four Spiritual Laws? Does it mean dressing weird? Does it mean putting tons of bumper stickers on the back of your car? Of course not.

• To love God is to first of all believe that He exists.
• To love God is to admire His character.
• To love God is to love what He loves and hate what He hates.
• To love God is to follow His decrees and commands.
• To love God is to pattern your life after Him.

And what does it mean to love your neighbor? Does it mean agree with or condone everything he does? Does it mean to roll over and do everything he wants you to? Does it mean offer him platitudes when he is poor, or in trouble, or depressed? Of course not.

• To love your neighbor is to treat him like you want to be treated.
• To love your neighbor is to seek his best interests.
• To love your neighbor is to not seek revenge.
• To love your neighbor is to open your heart, home, and wallet to his needs.
• To love your neighbor is to be happy for him when he wins, and mourn with him when he loses.

Or as a much greater writer put it:

If I speak in the tongues of men and of angels, but have not love, I am a noisy gong or a clanging cymbal.  And if I have prophetic powers, and understand all mysteries and all knowledge, and if I have all faith, so as to remove mountains, but have not love, I am nothing.  If I give away all I have, and if I deliver up my body to be burned, but have not love, I gain nothing.

Love is patient and kind; love does not envy or boast; it is not arrogant  or rude. It does not insist on its own way; it is not irritable or resentful;  it does not rejoice at wrongdoing, but rejoices with the truth.  Love bears all things, believes all things, hopes all things, endures all things.

Love never ends. As for prophecies, they will pass away; as for tongues, they will cease; as for knowledge, it will pass away.  For we know in part and we prophesy in part,  but when the perfect comes, the partial will pass away.

When I was a child, I spoke like a child, I thought like a child, I reasoned like a child. When I became a man, I gave up childish ways.  For now we see in a mirror dimly, but then face to face. Now I know in part; then I shall know fully, even as I have been fully known.

So now faith, hope, and love abide, these three; but the greatest of these is love.

1 Corinthians 13:1-13 (ESV)