Paul’s words are clear and to the point
Whatever a man sows that shall he also reap (Galatians 6:6)
The law of sowing and reaping is an universal and immutable law. It was true in ancient times, and it is true today. It applies to the physical world and to the world of the Spirit. It is a principle of order and consistency which is written into all life” (John Stott). The sooner a person learns and abides by the law of sowing and reaping the better life will be.
What is this law of the harvest?
First, it is an unchanging and unbending rule: whatever you sow is also what you will reap. You will reap in like amount as you sow and you will reap in nature what you sow.
Second, you must sow. That is, if you wish to reap, you must sow. Sowing always goes before reaping, and reaping comes in the same character and proportion as the sowing.
Third, you must consider how you sow. Good seed will produce a good crop. Paul meant this for both the physical world and the spiritual world. If we sow sparingly, we will likewise reap sparingly. If we sow “wild oats,” we will also reap wild oats.
Remember, it is not the reapers who determine the nature and abundance of the crop. That is determined by the sower.
Finally, this law of the harvest is determined by the Lord of the harvest. You can’t thumb your nose at God. Actually, that metaphor is what you find in the Greek meaning of the word “Mocked.” God cannot be mocked. You may fool yourself, but you cannot fool God.
Paul applied the law of sowing and reaping to the spiritual responsibility of meeting the needs of the teacher of the law. It is picture of the church. We will receive as give just as we reap as we sow.
He also applied this to how we live. If we neglect sowing, we will neglect reaping. If we sow badly, we will reap in like manner. “Whoever sows to pleas their flesh, from the flesh will reap destruction; whoever sows to please the Spiit, from the Spirit will reap eternal life” (Galatians 6:8).
Therefore, don’t give up about doing good and don’t get frustrated with the harvest. It will come in its own time if we do not give up.