You must be grounded in the practise of forgiveness. Keep your spirit fit by spending time praying in the Spirit and confessing your righteousness in God. Many in ministry have become ineffective because they have been wounded somewhere by the words and actions of others and are bleeding within.
Nobody can damage your work from without but if you allow their words to injure your spirit, the work will be stalled. Ministry is like engaging in a sport, an injury will cause a drop in performance levels. Always forgive, learn this early because you will have a lot of forgiveness to do along the way – Poju Oyemade(Ministry 101)