It's because in some ways, you don't believe you are worthy of receiving them yourself.
If you believe you are sinful and therefore guilty, because of something you think you did, you're going to be certain that you should NOT receive love. And because of that belief, you will be just as certain that other people should not receive love through you either.
You can walk this Earth for years under the oppression of that belief in sin, all the while blocking the expression of love, and therefore inhibiting God's miracles. Not only are you preventing yourself from being healed, but you're also keeping your brother in darkness and suffering.
This is not a guilt trip, by the way. I'm not trying to say, you darned idiot what do you think you're doing. I'm saying, God is OVERFLOWING with abundance of love for you and everyone, and WANTS to heal you and forgive you. But you're not letting Him.
If there's some big sin in you that you are quite sure can never be healed or undone or reversed or forgiven, it's so bad that nobody would love you because of it, then you're not going to allow or accept being unconditionally loved. And so if you don't believe you can be loved, forgiven and healed, you also aren't going to be WILLING to heal others.
When I accepted the atonement regarding what I thought was a real sin, discovering it was NOT real, and that therefore I was still innocent, I was overjoyed. I actually felt joy. Such a tremendous relief. And Jesus said to me "because you have received this for yourself, this will enable you to perform miracles".
The same is true for anyone. You have to be willing to dig out your sins and guilts and offer them up in the atonement, through forgiveness, to realize that you ARE forgiven because you DID NOT SIN. "And in that view, all your sins are forgiven." This will set you free!
You will then ALLOW, DESIRE, and WILL for yourself to receive love, because you will recognize that you are now WORTHY of love. This sense of worthiness comes because you can clearly see, in the atonement's truth that you did not really do what you thought you did, that this MEANS you are still innocent. That therefore means that you are still lovable. And therefore, you ARE worthy of love!
If you are worthy of love, then you will also be WILLING for love to be expressed to and through you, and therefore you will not only be WILLING to perform miracles for others, you will become ABLE to perform miracles for others, because you will have plugged yourself back into God's power strip and will no longer be obstructing the flow of power with your belief in sin.
If you have shame, unworthiness, loneliness, a sense of guilt or fear, any kind of regret, if you're sick, suffering, anything less than love, you KNOW there is some belief that you have that you're sinful. That because of something you REALLY DID and therefore REALLY ARE, you are no longer eligible for love. Well let me tell you this. You are fucking eligible for love right now and always because God Himself does love you with an unconditional, unlimited, non-expiring and absolutely perfect love which HAS NO LIMITS and cannot see you as sinful, no matter WHAT you think is true of you!
It's not a matter of whether God finds you worthy, or whether you can be loved, it's a matter of YOU not agreeing with it!