After reading your response to the question “Do We Have Our New Heart Yet?”, you stated that we will not get a new heart until after the rapture when we are changed. What about 2 Corinthians 5:17? It states that we are made new creatures the moment we believe and are saved. Doesn’t that include a new heart?
If you still sin, whether in thought, word or deed, it means you don’t have a new heart yet. You are considered by God to be a new creation because of who you are in Christ (2 Cor. 5:17). At the rapture you will become in fact that which you are now in faith, as your mortal body is instantaneously changed to an immortal one (1 Cor. 15:51-53). At that time you will receive a new heart and will no longer sin.