Verse 4 tells us that it is imperative that we teach our children and the generations that follow us the "wonderful works of God". More importantly yet, men are to be the ones that teach. For God first gave Jacob the testimony and made him Israel. Without this, the next generation cannot do the work of the Lord nor can the Lord work through them. To grow the Kingdom and bring His Glory to the Earth this is what we must do! If we fail in this command, the Lord can be lost from that generation, leading to their downfall and continued failures until God is known again. For without God, failure is a guarantee.
The wonders of Israel from the Old Testament are referenced here as examples of the the "wonders of God". Israel's lust for moar in the desert is part of what kept them there for 40 years. This and their unbelief. How do we as children of God keep our hearts from turning evil as the hearts of Israel did? Companionship with the Lord through prayer and ever increasing closeness with Him. We are not to limit Him in our lives. As Carrie Underwood says "Jesus, take the wheel". We have to allow Him to steer for us. Man is weak and frail in mind and spirit. Only with the Holy Spirit guiding us through our undying belief in God can we truly be the men God asks of us. Every chance we get to steer, Pray first. Pray second, Pray third. Let Him show us the way above all else.
As David was the mighty shepherd of God's people, we are called to do the same. David was guided by the Lord in all his ways. God granted David extreme gifts as David was to be the vessel of the Lord. God's integrity was a great gift to David and without it, David would not have risen to the heights he did. For the Lord moved David up to achieve great things in His own name and for His name. Not for the name of man. What things do we do to achieve great things for our Lord as compared to for ourselves? What heights do we desire to climb to and how will we honor God in those heights? God has our backs when He is in the front of our minds. Allow the Lord to shape your plans and be your guide. For whatever He calls you to do, will be the calling we must fulfill.