Titled commentary, from my scriptures notebook from my mission.
As difficult as it may be for use to rely on Christ and have faith in Him - we have a safe assurance of His actual existence because of His mortal ministry as recorded in the New Testament. But, still, trying as it is now, imagine how hard it must have been for the people of the Old Testament, waiting for a God of Redemption who was to come. We equally wait for the Lord to come again, and we can search the ancient scriptures to relate to the expectations of the promised Messiah. Inspired recordings of the Lord's mercy, kindness, and love have been thankfully given to us and to them so as to strengthen our faith in an event eagerly anticipated.
To many, the God of Israel may be seem as barbaric and warlike of the people that inhabited the earth, sending plagues, wars, destruction, and floods, yet if sought out scripturally both in text and example, we can see that our loving Savior was alive and active in the promised state, as Jehovah.
Because of an almost constant state of apostasy and unwillingness to obey, the choice kingdom of Israel was unable to receive direct clarifications as to the profound nature of their King and Lord (2 Nephi 28:30). Even to Moses, to whom the name and purpose of Jesus Christ was revealed personally (Moses 6:57), he was commanded to reveal the fact that to the young nation only in simple terms, as a Prophet (Deuteronomy 18:15), and in interesting symbolism, such as lifting up the brazen serpent (Numbers 21:8-9). The people of Israel had every right to a more correct knowledge of their Captain and Creator, yet they constantly proved themselves unworthy and unprepared for such general revelations. While the Lord was etching in stone tablets, "thou shalt have no other gods before me," (Exodus 20:3) the Israelites were at the foot of the mountain worshiping a golden calf (Exodus 32:4). The natural man always seems to understand better the things which require little effort or explanation, and so we turn to our false gods.
Yet, even amid general darkness, the Lord still saw fit to reveal in basic terms His coming mission. In comparison to the pagan gods that required human sacrifice, the Lord of Hosts gave commandments that would lead to build a better family, nations, and earth.
The Lord is always willing to condescend to succor His people, and one amazing way that he does so is by speaking in analogies that the people can understand. The same is true with the inhabitants of ancient Israel, and may partly describe why it is difficult for a modern generation to see the message, our cultures being widely different in nature.
In the psalms, or the hymns of old, the God of Israel is portrayed in a large scope of definitions, helping the people understand more clearly His true character. They can be grouped into three basic forms: Jehovah as the Rock, our protector, as a Shepherd, as merciful gatherer, and as the Judge, holding both mercy and justice. "Who is a rock save our God?" (Psalms 18:31)
Considering the constant shifting political situations of the old world, it's any wonder that the Lord would choose to describe Himself as a fortress, a stronghold, and the armer. Even the strongest men of men had need of gear if going to battle, and likewise we cannot do without the spiritual protection that can only come from above.