If in preaching the gospel you substitute your knowledge of the way of salvation for confidence in the power of the gospel, you hinder people from getting to reality.
Take care to see while you proclaim your knowledge of the way of salvation, that you yourself are rooted and grounded by faith in God. Never rely on the clearness of your presentation, but as you give your explanation make sure that you are relying on the Holy Spirit. Rely on the certainty of God's redemptive power, and He will create His own life in people.
Once you are rooted in reality, nothing can shake you. If your faith is in experiences, anything that happens is likely to upset that faith. But nothing can ever change God or the reality of redemption. Base your faith on that, and you are as eternally secure as God Himself. Once you have a personal relationship with Jesus Christ, you will never be moved again. That is the meaning of sanctification. God disapproves of our human efforts to cling to the concept that sanctification is merely an experience, while forgetting that even our sanctification must also be sanctified (see John 17:19). I must deliberately give my sanctified life to God for His service, so that He can use me as His hands and His feet.