Paul says, "Even though I received wonderful revelations from God...to keep me from getting puffed up, I was given...a messenger from Satan to torment me...I pleaded with the Lord...that it might depart ...And He said...'My grace is sufficient for you. My strength is made perfect in [your] weakness'" (See 2 Co 12:7-9 NKJV). Dealing with your old nature is a time-consuming, grace-developing, ego-destroying, character-building process that happens day-by-day, and sometimes moment-by-moment. When God's grace rubs against our stubborn wills and self-serving ways, a refining process happens that can't be rushed or accomplished any other way.
The Bible says, "The war between the house of Saul (which represents your old nature) and the house of David (which represents your new nature) lasted a long time. David grew stronger and stronger while...Saul grew weaker and weaker." Only as you're willing to strip away the pride, get down on your knees day by day and ask God to work in you, will you experience His life-changing power.