How sincere is our faith in Christ?

I came to realise that in God’s eyes, sincerity of faith comes before success. 

Luke 10:17 - 20 (NIV) 17 The seventy–two returned with joy and said, “Lord, even the demons submit to us in your name.”... 20 However, do not rejoice that the spirits submit to you, but rejoice that your names are written in heaven.”  

Too often we celebrate our successes.  Too often we forget to celebrate the sincerity of our faith.  How sincere is our faith in Christ?  What is our heart commitment to Him?