David's Army by Henry Morris, Ph.D.
 

"David therefore departed thence, and escaped to the cave Adullam: and when his brethren and all his father's house heard it, they went down thither to him. And every one that was in distress, and every one that was in debt, and every one that was discontented, gathered themselves unto him; and he became a captain over them: and there were with him about four hundred men." (1 Samuel 22:1-2)

As David was fleeing for his life from King Saul, a rather pitiful and unpromising company began following him, and they became the nucleus of what would soon be his army. Others joined them, and David trained them, "for at that time day by day there came to David to help him, until it was a great host, like the host of God" (1 Chronicles 12:22). Soon they were no longer discontented misfits, but a remarkable array of "mighty men" (v. 21). One group, for example, was said to be "men of war fit for the battle, . . . whose faces were like the faces of lions, and were as swift as the roes upon the mountains" (1 Chronicles 12:8).

In many remarkable ways David was a type of Christ, his life foreshadowing the experiences of the greater "son of David" who would come a thousand years later. In such a parallel, his army is a type of the earthly "host of God," the great company of those who have chosen to follow Christ, each of whom has been called to "endure hardness, as a good soldier of Jesus Christ" (2 Timothy 2:3).

The followers of Christ were once also in distress, for the "base things of the world, and things which are despised, hath God chosen" (1 Corinthians 1:28). He is now "the captain of their salvation" (Hebrews 2:10), urging that each one should strive to "please him who hath chosen him to be a soldier" (2 Timothy 2:4). When He is finally ready to take the kingdom, these will be with Him in His triumphant return and eternal reign (Revelation 19:14; 22:5). HMM

http://www.icr.org/article/6640/