In Isaiah 53:4-6
4Surely he took up our infirmities and carried our sorrows,
yet we considered him stricken by God, smitten by him, and afflicted.
5 But he was pierced for our transgressions, he was crushed for our iniquities;
the punishment that brought us peace was upon him, and by his wounds we are healed. 6We all, like sheep, have gone astray, each of us has turned to his own way; and the Lord has laid on him the iniquity of us all.

All of this, we know has ALREADY been done at the cross, on Calvary. What does that mean? That through the cross, our translation unto becoming children of God, our salvation, the place where Jesus died for our sins so that we may say yes to him, we have been granted all the following promises in those scriptures. Notice the past tense reference of each scripture. Meaning God has already given it to us.

1 John 3:8
. . . But the Son of God came to destroy the works of the devil. –New living translation

Once again the works of the Devil are already destroyed. By whom? Jesus Christ, the word.
We know that in the book of Job, he was righteous, yet many afflictions came upon him. The devil had no power over Job. God allowed those afflictions to come about to show the quality of Job’s faith in Him. The same is true for all TRUE Christians. We will be tested by all sorts of trials, but it is so that we may endure, and persevere unto perfection and to prove our faith in Him.
So it is true sometimes Christians fall ill but don’t let that deceive you to believe you need to go to a deliverance meeting to be set free.

John 8:36
36 So if the Son sets you free, you will be free indeed.

Like Job it could be a testing of our faith, and if you know what the Word says and have the faith then you can speak against the situation, according to the word and receive what God has promised you. If you are born again, you have the Holy Spirit:

1 John 4:4
You, dear children, are from God and have overcome them, because the one who is in you is greater than the one who is in the world.

God has giving you the Holy Spirit and through Him the power to overcome. He Himself has called us more than conquerors. If you Abide in Christ you have the power to overcome by the Spirit of God he has given you. Sometimes God will test you with trials so that you will strengthen your faith and depend on the power that he wants to release into you by the Holy Spirit. You have what it takes, you don’t need a deliverance meeting to overcome your situation just to go back to it again for a new problem. You have everything you need inside of you, the Holy Spirit, The Word of God, have faith and overcome.

Ask yourself the question: for those who constantly go to deliverance meetings, where do you suppose their faith is, in Jesus Christ or the meetings?

Remember God's power is released according to your faith. When the Centurion Soldier asked Jesus to heal his servant and told Jesus that he was not worthy to have Him come under his roof, but say a WORD and my servant will be healed. Jesus replied saying he had not seen faith like that in Israel. Where was the Centurions Faith? In God's WORD, and it had the power to heal, Jesu did not have to set up a meeting and lay hands on the servant, he just needed someone who Believed in his Word and came to Him with a request.

I'm not saying that some believers don't have t be delivered from things, but if you really pay attention, they are usually not consistent in the Word of God and Prayer, they might have a secret sin and/or haven't properly repented over a matter, or the more obvious, just don't believe.