"As you do not know the path of the wind, or how the body is formed in a mother's womb, so you cannot understand the work of God, the Maker of all things." NIV translation
Although we know the scientific answers to these questions today, the people of this time did not have any idea. We have much knowledge today but we still must be humble enough to say that we do not understand everything about God and His ways. It is easy to trust God when we understand how He is doing something but it takes true faith to trust Him when we do not have all of the answers. As Christians today, we have a huge advantage in the fact that we have a record of what God has done in the past (the Bible).
"Sow your seed in the morning, and at evening let your hands not be idle, for you do not know which will succeed, whether this or that, or whether both will do equally well." NIV translation
A true faith involves action. Because we trust that the things God has said are true, we know that our days are numbered until Jesus returns.
He has given us the ministry of reaching the lost and it involves many ways. We are to make good use of the time that we have and use whatever means we can to reach them.
"Light is sweet, and it pleases the eyes to see the sun. However many years anyone may live, let them enjoy them all. But let them remember the days of darkness, for there will be many. Everything to come is meaningless." NIV translation
As we go through life, there will be good days (days of sun) and bad days (days of darkness). True faith rejoices in both types of days as we remain focused on the fact that we will live forever with Him. Although God uses these days on earth to shape us and to grow us, we are reminded that the events of these days do not mean much when compared to eternity. We are to constantly look back (remember) the dark days and how God brought us through them. Each successful journey through a dark day builds up our faith and can even build up those around us.