A personal revelation of His goodness is absolutely foundational and fundamental for effective co-labouring with God. It is where boldness and confidence grows up and springs from. He wants to manifest His goodness through signs and wonders. He is looking for a people who will co-labour, pray and act out of a revelation of He is good. Sometimes we postpone our right to declare His goodness, believing that He can only use us when we are completely free. Now good character is crucial, He wants our character to be able to carry the power. But our ultimate confidence does not come from our character but from the gospel.  He does miracles through us by believing that His grace qualifies us and not by our works. (That is the topic of Galatians 3) The gospel empowers us with Biblical confidence to display His Kingdom.