alvation is a multifaceted reality. As a minister of the gospel, I generally stick to speaking of "soul salvation" - as I was commissioned to do. However, this psalm closes with a wonderfully clear reminder. Not only is God concerned about our soul, (Matthew 16:26) He cares for us in every way (I Peter 5:7 & Hebrews 4:15). David recognized the reasonableness of this assumption and indicated as much (Psalm 56:13). Paul agrees with this sentiment (Romans 8:32). If God was willing to give His only Son for the salvation of our souls, surely He would tend to be willing to give other things to merely take care of our material needs.
Now, David fought many times against a group of people who we know as the Philistines. Yet, in 1st Samuel 21:11-15 you can read of how he found himself right in the middle of their lair. He literally experienced the very real danger of standing alone in the royal court of his mortal enemies. There he slobbered on his beard, scratched on the doors and acted insane in order to escape.
David was certainly in a bad way. He was literally so alone (and afraid, and apparently out of focus) that he had gone to his enemies imagining that he might be safer there than in his own land. He said, "I will not fear" (Psalm 56:4), yet clearly, he was afraid (Psalm 56:3). Oh sure, he also committed Himself to God for help, but the fear factor was most definitely present. Yet, we must ask, was fear his greatest hurdle? Evidently not! The loneliness that David was enduring weighed heavily on him. Don't tell me that David was all tough and tumble. Oh, I know that he was a warrior and a king, but he was also a poet and a lover. So, in Psalm 56:8 we see that David was confident that God knew what he needed, and that He would provide in His good time (Matthew 6:8 & 32), but the emotional stress and misery was intense nonetheless. He knew his soul was secure, but it was his feet of clay which were hurting.