God told us the greatest of His commands is to love God with our whole heart, mind, soul, and strength. Jesus said if we love him, we will obey his commands. The most basic love we can give is the act of obedience. We show our parents that we love them by obeying them. We show love to God in the same way.
Fear the LORD your God, serve him only and take your oaths in his name. Do not follow other gods, the gods of the peoples around you; for the LORD your God, who is among you, is a jealous God and his anger will burn against you, and he will destroy you from the face of the land. (Deuteronomy 6:13-15 NIV)
Now, to be sure, love may not be our primary motivator for obedience. Fear may be at the top of the list. In the early years, we avoid what our parents say "no" to because they smack our hand or give us a spanking when they say the word. We don't want the punishment, so we listen to the "no." The same is true with God.
Be sure to keep the commands of the LORD your God and the stipulations and decrees he has given you. Do what is right and good in the LORD's sight, so that it may go well with you and you may go in and take over the good land the LORD promised on oath to your ancestors, thrusting out all your enemies before you, as the LORD said. (Deuteronomy 6:17-19 NIV)
With time, though, the fear of punishment doesn't become as strong a motivator. We want to see some positive reason for following the rules. We start to look for the WIIFM (what's in it for me). God gives great promises to people who will follow Him. Just like the promises He gave to the Israelites.
The LORD commanded us to obey all these decrees and to fear the LORD our God, so that we might always prosper and be kept alive, as is the case today. And if we are careful to obey all this law before the LORD our God, as he has commanded us, that will be our righteousness." (Deuteronomy 6:24-25 NIV)
The beautiful thing about obedience with God is the result: righteousness. This may not seem like a great thing if you are working out of fear or even WIIFM all the time, but it is a great result. Being right with God means you have an open channel of communication for a good relationship with God. Loving obedience, to be sure, is a very basic level of love for God...but it's a start. It sets us up to experience even greater kinds of love.