God promised His people that if they obeyed His commandments they would not get sick - Ex 15:26. As a child of God you are one of His people. In this dispensation Jesus left you with two commandments - Matt 22:36-40 - with one word in common - love. As you translate Ex 15:26 into this dispensation then it's clear that obeying the commandments to love will ensure your freedom from sickness and disease.
Friend Jesus already died on the cross and was resurrected. He bore our sicknesses and diseases - Is 53:5 - so that we don't have to be sick. You see you were healed over 2,000 years as a result of the sacrifice of Jesus. One of the ways that you remain immune to sicknesses and diseases is to consistently walk in the love of God. You must resist every temptation to walk contrary to the God-kind of love with the help of the Holy Spirit - Rom 5:5.