On Romans 3:21 – [C]an there be two words which are more blessed and more wonderful to us than just these two words, ‘But now’?  To me they provide a very subtle and thorough-going test of our whole position as Christians.  Would you like to know for certain at this moment whether you are a Christian or not?  I suggest that this is one of the best tests.  As I repeat these words, ‘But now,” is there something within you that makes you say, ‘Thank God!’  Is there a ‘But now’ in your experience?  – D. Martyn Lloyd-Jones, Romans Vol. 3, Pg. 26