You know, it really isn't too hard to see those that 'claim to know God, and follow His ways' and those that 'truely know God, and follow His ways'. When God is truely in your heart, He changes you. The old you really does die and out sprouts this person that is totally different than before.
For example, before I actually became a 'true' Christian. I said I knew God, I said that He was in my heart, and I was saved. Yet, I was full of unforgiveness, I was full of anger, and hate. I watched and read inappropriate movies and books, I flooded my mind with occult, I read horoscopes, astrology, I dabbled in other religion, ect. Yet I was a 'christian', and it was all a lie. You can't know God, I mean truely know Him, and continue in the ways of the world whole heartedly. You can't claim to be full of His Loving Spirit, and continue to hate. God said it was impossible to serve two masters, and it's true. If you serve the world, and go after the things of this world, you can't serve God, and vice versa.
When you have God in Your Life, He takes over. He takes away from you the ways of the world, and replaces them with His Ways. I look back at the person that I was, and the person I am now, and I see such a difference. And I praise God, for the work that He has done in me, and continues to do.
Of course, I fall sometimes, into the 'old' ways, but God is always there to pick me up, and set me back on His Path. He corrects my behavior, and He teaches me what is right. It truely is a miracle what He does for His Children.
And sadly, I see the same thing in others. Like I was before, they claim to know the Father, to follow His ways, and yet they are the same person they were before. They still seek the ways of the world, still go after the desires of the Flesh. They praise Him with their lips, but yet they don't let him into their hearts, they don't let Him move in their lives, their lives mock Him. They accept His Mercy, Yet don't give it. They accept His Grace, Yet don't give it it. It is meaningless worship, for He is truely not in them. Just as I was before, it meant nothing, because it was all a show before man. And God does not reward those that do their deeds before man, and His Spirit, His Love, His Heart, all of Him is our reward. He is the ultimate treasure that needs to be sought after, He alone is the desire of our heart, and the best part is, He Promises, that if you seek Him with all Your Heart, You will find Him. He doesn't want a half hearted attempt, He will not accept you on your terms, he will not accept only part of you, He will not be a backup incase something else doesn't work. He is a jelous God, and will not be second place to anything. He wants you whole hearted. He has to be number one in You life. He wants to take from us, all the parts that aren't of Him, and replace His Character, His attributes, His Ways, filling us with all that He is. It is His Will that shall be done, not ours, and the same with His Gift. The Gift of His Spirit, we cannot put on a shelf to use when we want. His Spirit fills us, and changes us, and molds us, and shapes us. What you were before dies, and the new creation lives.