In the army you are kitted, and begin basic training. You stay in barracks. You live detached to society.
As a Christian you are kitted inwardly,begin basic praying, and Bible reading. You stay where you are. You live detached to society.
In the army, you learn to march, do map reading take orders. You do team work.
As a Christian you march in step with Jesus,read the Bible as if it were your map and take orders directly from God. You play a part in God's overall team, but you might be called to more individual effort.
In the army you serve your country and maybe your monarch. You are paid a monthly salary. You are given honours and praise if you serve in campaigns or for a long time.
As a Christian you serve the kingdom of heaven, and God, the king. You are paid by the minute, hour, day, week, month by the increasing of your glory. You are again paid in heaven, even more. You are given honours and praise from God the Father.
In the army you need to get and stay fit.
As a Christian, you need to read the Bible to get spiritually fit.You need to do it each day to stay fit. Physical fitness can be useful but not as much as spiritual fitness.
In the army you draw weapons from the armoury. And handle them. Single shot rifles, pistols, heavy machine guns, grenades, etc. Through practice you learn to be effective using them.
The Christian draws weapons from the armoury. Prayer, Bible reading, speaking the word, etc.. “For though we live in the world we are not carrying on a worldly war, for the weapons of our warfare are not worldly but have divine power to destroy strongholds. We destroy arguments and every proud obstacle to the knowledge of God, and take every thought captive to obey Christ. “ Corinthians 10.3-5
In the army you may need a lot more firepower to do a job small arms can’t. So you call upon the most effective larger weapons. That will definitely shift the enemy.
A Christian will need more firepower to do a job which normal prayer can’t. So you fast, partial fast, or eat vegetables. That should shift the enemy.
In the army you train to fight a war in the natural realm. You may or may not have experience in a real war.
A Christian is in a spiritual battle from day one. You gain battle experience right away.“Our Struggle is not against enemies of blood and flesh, but against the rulers, against the authorities, against the cosmic powers of this present darkness, against the spiritual forces of evil in the heavenly places.” Ephesians 6.12
In the army you are treated in the infirmary for injuries.
The Christian goes to the Bible for healing from spiritual attacks.