Ps. 119:11 says, "I have hidden your word in my heart that I might not sin against. you."
One of the inherent dangers of being a preacher is that we spend so much of our time proclaiming the Word that we constantly look to the Scriptures for principles or truths that we can use to help someone else.
Often times, we neglect hiding the Word in our heart for ourselves. It's the hidden Word of God in our heart that keeps us pure and righteous and and free from sin.
Don't be like the train conductor who that falsely believes he has been to the places he announces just because he has loudly proclaimed them. Spend time in God's word first and foremost for your personal benefit. Then, out of the outflow of the Word and Spirit's activity in your own life, will come your best messages for others.