Deuteronomy 17:19-20 And it shall be with him, and he shall read therein all the days of his life: that he may learn to fear the Lord his God, to keep all the words of this law and these statues, to do them: that his heart be not lifted up above his brethren, and that he turn not aside from the commandment, to the right hand, ot to the left: to the end that he may prolong his days in his kingdom, he, and his children, in the midst of Israel.
In the context, Moses is speaking of the king of Israel, that he should read the Book, believe God, and keep the words of this law. This actually happened when the book of Deuteronomy was found in the temple and read to King Josiah. Josiah heard, believed, and did the Word of God. As a result he started a major reform and brought the people back to God. It all started with the response of reading the Word.
This response also applies to all of us, every believer: read the Word of God! Our response to the Gospel is to be in the Word daily and weekly, to fear (believe) God, keep it and do what the Lord says. We do not really see or fully understand the blessings and benefits that come into our life from hearing God in private, with the family, in small groups, and in the Divine Service. But it makes a difference.
We respond to the Lord by being in the Word often, both because God commands it and because He promises rich blessings and a good life as a result. In addition, we hold fast to Law and Gospel, turning aside neither to the right nor to the left. This means we do not compromise, rationalize, water down, or make excuses. We stay on the narrow path of Jesus alone. “Blessed are they that hear the word of God and keep it.” “Faith comes by hearing.”