Verse 13. God's help shall inspire us to help ourselves. Faith is neither a coward nor a sluggard: she knows that God is with her, and therefore she does valiantly; she knows that he will tread down her enemies, and therefore she arises to tread them down in his name. Where praise and prayer have preceded the battle, we may expect to see heroic deeds and decisive victories.
Through God is our secret support; from that source we draw all our courage, wisdom, and strength.
We shall do valiantly. This is the public outflow from that secret source: our inward and spiritual faith proves itself by outward and valorous deeds.
He shall tread down our enemies. They shall fall before him, and as they lie prostrate he shall march over them, and all the hosts of his people with him. This is a prophecy. It was fulfilled to David, but it remains true to the Son of David and all who are on his side. The Church shall yet arouse herself to praise her God with all her heart, and then with songs and hosannas she will advance to the great battle; her foes shall be overthrown and utterly crushed by the power of her God, and the Lord's glory shall be above all the earth. Send it in our time, we beseech thee, O Lord.
HINTS FOR PASTORS AND LAYPERSONS
Verse 13. How, when, and why a believer should do valiantly.