"How much more important is such carefulness to ensure success in the conflict of life. It is not mimic battles in which we are engaged. We are waging a warfare upon which hang eternal results. We have unseen enemies to meet. Evil angels are striving for the dominion of every human being. Whatever injures the health, not only lessens physical vigor, but tends to weaken the mental and moral powers. Indulgence in any unhealthful practice makes it more difficult for one to discriminate between right and wrong, and hence more difficult to resist evil. It increases the danger of failure and defeat. MH 128.3"
"For we wrestle not against flesh and blood, but against principalities, against powers, against the rulers of the darkness of this world, against spiritual wickedness in high places."
The EGW passage explicitly refers to a warfare against unseen enemies and evil angels striving for dominion over humans. This directly echoes the language and concept of spiritual warfare described in Ephesians 6:12, which speaks of wrestling against principalities and powers. The connection is strong and direct.