“These people come near to me with their mouth and honor me with their lips, but their hearts are far from me.” Isaiah 29:13
Sometimes we openly and deliberately defy God. Other 
times we try to resist him in passive ways, giving God the silent treatment as we refuse to pray, worship, or even talk about him. Another strategy we sometimes use for resisting God may be the worst of all. We pretend to be following God. We merely go through the motions, looking okay on the outside, fooling even the most keen observers and maybe even fooling ourselves.
We can do that same thing in many other areas of our lives. We may dutifully go through the motions of fulfilling our spouse’s demands, our boss’s demands, our kid’s demands, while inwardly resenting the burdens placed on us. We may technically do the tasks that are put upon us, but inwardly we’re not doing them willingly. When we have this attitude toward God it is doubly bad because, for one, He cannot be fooled and two, pretending leads our lives into destruction.
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There is a story about a little boy who is told to stand in the corner by his mother. He defiantly sits in the corner. He is mother tells him to stand up. He stands, but yells back over his shoulder, “I may be standing on the outside, but I’m sitting on the inside.” When we look like we are taking a stand for God, but are actually “sitting on the inside,” we can’t fool anyone for long. Eventually the charade will catch up with us. Sincerity of heart has always and will always be how God views our actions. When our kids were kids (some of you remember), we didn’t like it if a task was assigned and they rolled their eyes. Rolling the eyes is a show of dissatisfaction with the task at hand. Too often we roll our eyes at God when doing work for Him.
If we appear to be participating wholeheartedly in the things of God, but it’s mostly for appearances, we will not grow. We will be eventually hit by something that requires “realness.” If we have spent all our time learning to fake it, we will be unprepared for times of actual spiritual need. A counterfeit bill might get by before it is tested, but once it is tested it is worthless. The same goes for us. 
If we sing in worship or participate in a Bible study, but our participation is a pretense having to do with what we should do rather than what we want to do we will eventually be found out- usually under fire. We have counterfeited honoring God and it will not stand true scrutiny.
When I was young, my brother, sister and I used to put records on and fake like we were singing and put on concerts for our parents and other family members. We sounded just like the Beatles or Dave Clark Five or a hundred other groups. When I tried out for choir in sixth grade, I think I was the only one not to make it. Acting like a singer did not make me a singer. Acting like a servant of 
God does not make us servants of God. Being a servant of God does. One of the scary aspects of “religion” is that we can easily “fake it.” But we are not in a religion, but a relationship. That is harder to fake.
It is possible to go through the motions in church for years while carefully keeping God at arm’s length. The result is usually a religiosity that lacks a real relationship. Without that relationship there is no joy, no peace, no satisfaction. Eventually, they say, “all pretenders will be separated from true contenders.” I think that is true. Remember, we are called to contend for the faith. We can’t do that by pretending.