"And thou shalt love the Lord thy God with all thy heart, and with all thy soul, and with all thy mind, and with all thy strength: this is the first commandment." Mark 12:30
When Jesus answered the question about which commandment was the greatest, He did not include loving God with all your mouth- it was your heart, soul, mind and strength. So many people want to love Him with their mouth only. They talk about loving Jesus, they profess they love Him with their words, but that's the only "evidence" that you see in their lives- their words.
Lip service was not in the definition of true love toward God. Any one can "say" they love God, but words are often cheap, empty and hollow. God's desire is that we love Him with our heart, not our words. Our words are backed up by action. If our words of love for God are words only, you'll know it by the actions because the actions will be contrary to what the definition of true love is. If our words of love for God are true words of love that come from our heart, they will be followed up by deeds and actions that honor and glorify God. Let me give you an example of what I am talking about that fits both- true love from the heart and mere words of love. Jesus said that if we love Him we will keep His commands. If you say you love God and are keeping His commandments, then it is love from the heart because your actions have backed up your profession. If you say you love God but don't keep His commandments then it is "love from the lips" only- which is not love at all.
If you are merely talking about loving God or loving Jesus but aren't backing it up with your actions and don't mean it from your heart, then you have already broken the first and greatest commandment. So right up front and at the beginning you have proved that all you have is a love from the lips and not from the heart. And love from the lips is not true love for God at all.
Have a great day. He didn't say to love Him with your lips but with your heart. Just because you "say it" doesn't mean that you really love Him. But if you mean it, you will say it and your actions will prove it.
For further reading:
John 14:23,24; 15:10
1 John 2:3-5