God is always giving us instruction to come up higher and to become more like Him. To conform to His way of doing and being right rather than living as the world lives.
Romans 12:2 Do not be conformed to this world (this age), [fashioned after and adapted to its external, superficial customs], but be transformed (changed) by the [entire] renewal of your mind [by its new ideals and its new attitude], so that you may prove [for yourselves] what is the good and acceptable and perfect will of God, even the thing which is good and acceptable and perfect [in His sight for you].
God tells us not to conform to the world’s way of doing, not to adapt to their superficial customs, in order that we can live in His perfect will and so we can be the witness He is calling us to be. He is asking that we change the way we think to think His way, to live by His ideal ways, by His opinion, so that we can live in and prove His good and perfect will.
When we prove the goodness of God by being an example for God, we can be effective in proving to others His will for us is good. Many believe God is not good or God doesn’t care, and that is because we as Christians are not doing our part in proving His will is good and perfect in our own lives
Mark 4:24 And He said to them, Be careful what you are hearing. The measure [of thought and study] you give [to the truth you hear] will be the measure [of virtue and knowledge] that comes back to you—and more [besides] will be given to you who hear. 25 For to him who has will more be given; and from him who has nothing, even what he has will be taken away [by force].
Jesus instructs us to be careful what we hear revealing to us that as we hear, we will get the right knowledge by making His way our way. The more we look at the Word of God, the more we listen and take heed, the more understanding we will have and the more understanding we have, the more blessings we can live in.
If we are not paying attention to what He said, even the little we did know will be stolen from us. Satan is a thief and if we are not careful what we hear he will take what we already knew.
It is easy for the enemy to contaminate our thinking if we are not careful about what we are hearing. For example, the killing on television has been so much of what is portrayed that it is considered to be normal and has become our real life scenario. For almost any reason life is not valued in the world's way of doing. Many have conformed to what they have been putting their eyes to. Watching whatever is on television, not paying attention to what they hear over and over, outside of the Word of God, has resulted in disregarding the Word of God, disregarding virtue.
Even in watching what is looked at as a Christian movie, the power of God is taken away by not having the knowledge of and conforming to God’s Word. Sickness for example, is portrayed as God helping us through sicknesses, opposed to what the Bible says; by His stripes we were healed - isn’t mentioned. Therefore as we conform to what we hear, we don’t get healed. The Christian movie instead represents God as a God who wants His children to endure sickness and disease.
Jesus didn’t take those stripes for show but for our healing. We don’t have a revelation of that because we are not careful of what we hear. We don’t hear the Word and apply the Word to our lives therefore we don’t live it.
Isaiah 53:4 Surely He has borne our griefs (sicknesses, weaknesses, and distresses) and carried our sorrows and pains [of punishment], yet we [ignorantly] considered Him stricken, smitten, and afflicted by God [as if with leprosy]. 5 But He was wounded for our transgressions, He was bruised for our guilt and iniquities; the chastisement [needful to obtain] peace and well-being for us was upon Him, and with the stripes [that wounded] Him we are healed and made whole.
Yes God uses doctors and helps us endure because that's where we are. God won’t / can’t work outside of what we believe, so what little faith we give Him is what He little faith He has to work with.
Proving His will is good and perfect is living by His opinion(what He said), conforming to His way and having His will happening in our lives rather than ours. Therefore to be healed for example; we have to conform to what He said and using our faith to receive what He said; starting with paying attention to what we hear.
Romans 10:17 So faith comes by hearing [what is told], and what is heard comes by the preaching [of the message that came from the lips] of Christ (the Messiah Himself).
Paying attention to the Word will bring us faith, and the revelation knowledge we need to receive His promises; proving His will is good and perfect.
Mark 4:26 And He said, The kingdom of God is like a man who scatters seed upon the ground, 27 And then continues sleeping and rising night and day while the seed sprouts and grows and increases—he knows not how. 28 The earth produces [acting] by itself—first the blade, then the ear, then the full grain in the ear. 29 But when the grain is ripe and permits, immediately he sends forth [the reapers] and puts in the sickle, because the harvest stands ready. 30 And He said, With what can we compare the kingdom of God, or what parable shall we use to illustrate and explain it? 31 It is like a grain of mustard seed, which, when sown upon the ground, is the smallest of all seeds upon the earth; 32 Yet after it is sown, it grows up and becomes the greatest of all garden herbs and puts out large branches, so that the birds of the air are able to make nests and dwell in its shade.
Thus, when we renew our minds with the Word of God we are planting seeds that will grow and before we know it, the Word sprouts producing faith that can then produce our healing or whatever it is you are believing God for.
In summary; To renew our minds we have to change what we are hearing and when we change what we are hearing, we can change our circumstances. When we change our circumstances we are living as a witness for God, receiving all He has already made provision for us-proving His will good and perfect.