Read Ecclesiastes 11.
The wisest who ever lived did not know everything. Four times in six verses Solomon tells us some things we do not know.
1. You do not know what may happen with an investment. (vv.1-4)
Generosity and/or investing in opportunities always carry risks. One can never tell how coming to the aid of another person or an organization may reap dividends. But nothing ventured means nothing gained. Many never give to their church or to help others. Some never invest in things that matter due to selfishness, laziness, fear of what might happen, or procrastination (v.4). Profits and rewards only go to those who gave of themselves and their resources.
"Whoever is generous to the poor lends to the LORD, and he will repay him for his deed." (Proverbs 19:17)
2. You do not know how human life is formed. (v.5a)
Certainly, the process of is known. Babies are born. But the intimacy and intricacies of what God does in the womb to bring all the physical, spiritual and personal elements together is a mystery.
"For you formed my inward parts; you knitted me together in my mother's womb. I praise you, for I am fearfully and wonderfully made." (Psalm 140:13-14a)
3. You do not know the work of God. (v.5b)
This is the completion of the thought above. Not only is human life the work of God, but everything is His. We can see the results of the LORD's handiwork, but we do not know what, when and how He will move next. Jesus said that the way of the Spirit is like the wind. We do not see the wind; only the effects (John 3:8). As Sovereign Creator, He is the rightful Owner and Sustainer of all things.
"The earth is the LORD's and the fullness thereof, the world an those who dwell therein." (Psalm 24:1)
4. You do not know what will lead to success. (v.6)
The illustration is of a farmer sowing seed. He is totally dependent upon the soil, the sun, the amount of rain, and timing. All out of his control. Yet, if there is to be a harvest, he must go to work. He will work hard. He will probably diversify into planting more than one or two crops to increase the possibility of increased profits. Then, after he has done all he can do, he must trust God for the outcome.
"So...whatever you do, do all to the glory of God." (1 Corinthians 10:31)