1. "Sow to yourselves in righteousness"  This means to stop sinning and start doing what is right in all things—to consecrate to do that which is good and right. Sowing and reaping always stand out against each other, as labor and reward! (2 Corinthians 9:6; Galatians 6:7-9).
2. "Reap in mercy” This means to accept and appropriate the mercy of God extended to us. If we do not accept mercy from God it will not be ours, for both sowing in righteousness and reaping in mercy are our responsibility. Righteousness is here to do, and mercy is here to receive, but neither will be a man's experience until he does what is right and accepts the mercy provided.
(Matthew 5:7; Mark 11:25-26)
3. "Break up your fallow ground” This also is the work of man. Each must break up the ground of his own life (your heart). Fallow ground is that which has been plowed but not sown; ground not in use; idle ground crusted over and hardened until it needs to be broken up again to receive the seed. Our hearts and wills must be broken and yielded to God. We must make ourselves willing to receive the Word of God and to obey it or seeking Him will not avail us anything.
(Matthew 13:3-12, 18-23; James 1:18, 21; 1 Peter 1:23)
4. “Preparing the way of the Lord” (Isaiah 40:3) is used here figuratively, heralding the coming of the Messiah.  It was the custom in the East to send a party of men before a king or a prince to prepare the way before him. They cleared the way of thorns, brambles, and bushes; made bridges; found fording places in the streams; and leveled the ground wherever necessary to make it easier for travel. This kind of custom could be applied figuratively of the preparation of the people to receive Yeshua, the (coming) Lord of Host!

But he that received seed into the good ground is he that heareth the word, and understandeth it; which also beareth fruit, and bringeth forth, some an hundredfold, some sixty, some thirty. (Matthew 13:23)
Good, because prepared by taking out the stones & thorns and plowing and properly preparing the ground to grow wheat. Fruit bearing depends upon the kind of soil and proper care in cultivation!
But other fell into good ground, and brought forth fruit, some an hundredfold, some sixtyfold, some thirtyfold. (Matthew 13:8)

But without faith it is impossible to please him: for he that cometh to God must believe that he is, and that he is a rewarder of them that diligently seek him. (Hebrews 11:6)
Here we see the absolute necessity of faith and the secret of pleasing God. You have to come to God in the right attitude and with the right motives!  (Matthew 6:5-15; Matthew 7:7-11; Phil. 4:5-6).To believe that He is a rewarder of them that diligently seeks Him. If one can believe this as much as he believes in the existence of God, prayer will be granted. If one believes firmly in His existence and doubts His word, he makes Him a liar and God is under no obligation to answer prayer (James 1:4-8).
Call unto me, and I will answer thee, and shew thee great and mighty things, which thou knowest not. (Jeremiah 33:3) You walking & serving God daily or you are under the enemy’s dominion!