"Physical inaction lessens not only mental but moral power. The brain nerves that connect with the whole system are the medium through which heaven communicates with man and affects the inmost life. Whatever hinders the circulation of the electric current in the nervous system, thus weakening the vital powers and lessening mental susceptibility, makes it more difficult to arouse the moral nature. Ed 209.2"
"I beseech you therefore, brethren, by the mercies of God, that ye present your bodies a living sacrifice, holy, acceptable unto God, which is your reasonable service."
Both passages connect the physical body with spiritual life. Romans 12:1 calls for presenting the body as a living sacrifice, while the EGW passage describes how physical inaction can hinder moral power. The connection is thematic, focusing on the body's role in spiritual life.
"Again, excessive study, by increasing the flow of blood to the brain, creates morbid excitability that tends to lessen the power of self-control, and too often gives sway to impulse or caprice. Thus the door is opened to impurity. The misuse or nonuse of the physical powers is largely responsible for the tide of corruption that is overspreading the world. “Pride, fullness of bread, and abundance of idleness,” are as deadly foes to human progress in this generation as when they led to the destruction of Sodom. Ed 209.3"
"Behold, this was the iniquity of thy sister Sodom, pride, fulness of bread, and abundance of idleness was in her and in her daughters, neither did she strengthen the hand of the poor and needy."
The EGW passage directly quotes Ezekiel 16:49, making this an explicit allusion. The context in both passages is also similar, discussing the dangers of pride, idleness, and excess.
"Teachers should understand these things, and should instruct their pupils in these lines. Teach the students that right living depends on right thinking, and that physical activity is essential to purity of thought. Ed 209.4"
"What? know ye not that your body is the temple of the Holy Ghost which is in you, which ye have of God, and ye are not your own? For ye are bought with a price: therefore glorify God in your body, and in your spirit, which are God’s."
Both passages emphasize the importance of the body as a temple and the need to glorify God through it. EGW's statement about physical activity being essential to purity of thought aligns with the concept of glorifying God in the body.
"For as he thinketh in his heart, so is he: Eat and drink, saith he to thee; but his heart is not with thee."
Both passages connect thoughts and actions/character. However, Proverbs 23:7 focuses on hypocrisy, while EGW focuses on the general principle of right thinking leading to right living. Therefore, it's a thematic parallel rather than a direct principle.