lthough David was a fierce and courageous military man, he was no stranger to retreat. During the days of Saul, and later when his son Absalom rose up against him, David took to fleeing rather than fighting. Not that David was afraid; he fled from his father-in-law because of principle and from his son in wisdom. Yet, retreat was surely not easy for David. In fact, we have good reason to believe that David still had a willingness to fight beyond the time when he actually had the physical vigor to do so.
In any case, God was the foundation of David’s success... not David himself. I Corinthians 3:11 teaches us that God is the support upon which the righteous stand, and truly that foundation can't be destroyed, although admittedly, we can certainly do temporary damage to His reputation locally... that is, if we aren't careful, we can easily demote Him in the eyes of some men.
While we should all readily admit that ultimately God is our Rock, our cornerstone and foundation, the word foundation can be used more broadly. In I Timothy 3:15 Paul calls the church a foundation of sorts. In our day, the question must be asked, if a church is destroyed (we can't say THE church, because that would be impossible - see Matthew 16:18), what impact will that have on the righteous children of God who were connected to that congregation? Yes, our trust must remain in the Lord (Psalm 11:1) and not in men. But, the ungodly are always poised and ready to take down believers at any opportunity (Psalm 11:2).