It is amazing how gullible and easily deceived people can be, but nobody can deceive God. We are told in 1 Samuel 16 v 8, "The Lord seeth not as man seeth; for man looketh on the outward appearance, but the Lord looketh on the heart." We are also told in Jeremiah 17 v 10, "I the Lord search the heart." Jesus knowing what was going on in the hearts of the scribes said, “Why reason ye these things in your hearts." (Mark 2 v 8).
Sadly, believers in Christ can be tempted to try and give an outward impression of spirituality. You can talk and pray in a very pious way. It can result in other believers being deceived into thinking you are ever so holy but you don't deceive family and especially God. God sees us as we really are, also He sees the motives and desires in our hearts. It speaks in 2 Corinthians 5 v 12 of those who glory in appearance, and not in heart. The Pharisees liked to give an outward impression of godliness but Jesus who searches the heart describes them as, "Whited sepulchres which appear beautiful outwardly, but are within full of dead men's bones and all uncleanness” (Matthew 23 v 27). The believers in Christ at Sardis gave the outward impression to others they were ever so spiritually alive but Jesus who searches the heart says to them that they are spiritually dead (Revelation 3 v 1).
We are totally missing the point if we try to outwardly give the impression to others of a holiness and godliness we don't actually possess. It may deceive others but what's the point because God knows exactly the person you really are. He sees your heart and life everyday no matter where you are. So get rid of all outward pretence of godliness and spirituality from your life and realise that God knows how godly and holy you really are!