God's will is permanent healing, and miracles extend this, coming from love. So if there is any way that you believe healing will not happen, that means you don't believe God's will, so are actively working against it.
God has certainty and a complete knowing that healing has already occurred. We need to share in this.
This is why when you go to perform a miracle, you also need to believe in what God believes. You need to have this certainty that healing will and has happened. And what that translates to, is that you need to EXPECT MIRACLES TO HAPPEN.
Expectation comes when your belief is so refined and certain, that you are convinced and sure that it will happen. This puts you into a state of expecting, which in a way is a form of demanding/commanding. It is a refusal to accept any other outcome. Complete certainty.
Expectation is a very firm way of not only believing but of actively EXTENDING the certainty of God that "healing is truth". It's like, "of course it will heal!", or even better, "it MUST heal". No doubt. This is where you are extending God's authority over illusions.
Once all doubt and fear are gone, which is a requirement of miracle-mindedness, expectation results as a perception of certainty. It's not a request, it's an enforcement of God's will.
When there is no doubt left that healing must occur, in which you are merely enforcing God's will kind of like a law-enforcement officer, you KNOW the law and you KNOW what God wants and you KNOW that this is not negotiable. As such, what is left but to completely expect, reliability, certainty, trust... that "it is so". Illusions must bend to this because they have no authority over God.
Expect miracles to happen, believe it totally, pray with God and receive.