The Word is very clear that physical healing is also included in the atonement for ALL. Read Isaiah 53 prayerfully and dependent upon the Holy Spirit and see for yourself.
Sickness and death entered the world through sin. Thus, sin is the very root or entry point of sickness.
And what did Jesus do?
Not only did He heal us by His stripes (1 Peter 2:24) but He also atoned for sin thus destroying the very root of sickness – sin – and EVERYTHING that “grew” out of it. It’s up to each of us. We can either take Him for His Word or not. God says that Jesus paid for healing in full for all in the atonement, I believe it, and you can too.
God’s Word is life and health to our bodies. Here’s a free printable, all based on scripture, that you can use to “dose” the Word to your child who needs healing.