"“‘Let the members of the church have increased faith, gaining zeal from their unseen, heavenly allies, from a knowledge of their exhaustless resources, from the greatness of the enterprise in which they are engaged, and from the power of their Leader. Those who place themselves under God's control, to be led and guided by Him, will catch the steady tread of the events ordained by Him to take place. Inspired by the Spirit of Him who gave His life for the life of the world, they will no longer stand still in impotency, pointing to what they cannot do. Putting on the armor of heaven, they will go forth to the warfare, willing to do and dare for God, knowing that His omnipotence will supply their need.’ LS 474.1"
"Put on the whole armour of God, that ye may be able to stand against the wiles of the devil."
Both passages encourage believers to equip themselves spiritually for a battle.