"The church of Christ may be fitly compared to an army. The life of every soldier is one of toil, hardship, and danger. On every hand are vigilant foes, led on by the prince of the powers of darkness, who never slumbers and never deserts his post. Whenever a Christian is off his guard, this powerful adversary makes a sudden and violent attack. Unless the members of the church are active and vigilant, they will be overcome by his devices. 5T 394.1"
"Thou therefore endure hardness, as a good soldier of Jesus Christ."
Both passages use the metaphor of a soldier to describe the Christian life, emphasizing the themes of hardship, toil, and the need for endurance. The EGW passage expands on this metaphor, but the core idea is present in both.
"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."
Both passages describe the Christian's struggle against spiritual forces of darkness. Ephesians 6:12 provides the theological basis for this struggle, and EGW applies it to the need for vigilance and activity within the church.
"The Master calls for gospel workers. Who will respond? All who enter the army are not to be generals, captains, sergeants, or even corporals. All have not the care and responsibility of leaders. There is hard work of other kinds to be done. Some must dig trenches and build fortifications; some are to stand as sentinels, some to carry messages. While there are but few officers, it requires many soldiers to form the rank and file of the army; yet its success depends upon the fidelity of every soldier. One man's cowardice or treachery may bring disaster upon the entire army. 5T 394.3"
"For the body is not one member, but many."
Both passages use the analogy of a body/army to illustrate that each member has a specific role and is important for the overall success of the group.