1 Timothy 4:1-5
The natural direction of the human heart is inclined away from God. Therefore we will drift from Him until we have moved far enough to run from Him. Some will hold onto the pretense that they are followers of Christ but with no real intention of actually acting in a manner worthy of Him. Here is brief comment by John Calvin regarding this.
Calvin – “Men being by nature inclined to hypocrisy, Satan easily persuades them that God is worshipped aright by ceremonies and outward discipline; and, indeed, without a teacher, almost all have this conviction deeply rooted in their hearts.” (from his commentary on 1 Timothy 4:1)