Kingdom business is difficult because I have a king who is righteous and demands righteousness from all his servants (me included), yet I know I am flawed, imperfect due to my sinful nature. Doing business in the kingdom demands that we deal with one another's sins. The disciplines of confession, repentance, and forgiveness are a must in order to succeed in our service. People who have difficulty exercising or refuse to exercise any of these disciplines don't understand the kingdom of God at all.
Now let's add to the personal sinfulness of each servant in the kingdom the fact that we serve in an evil world. There are other people in the world who do not care for the kingdom at all. These are the sons of the evil one. Jesus explains in his Parable of the Weeds that there is a work of the enemy in the world; people who reject and even persecute God's servants. When asked about uprooting the weeds, Jesus is against it lest the wheat is uprooted along with the weeds. Kingdom business is not about leading a crusade to eliminate infidels. It is about enduring the hatred and persecution of those infidels with the love that God can only give until the end of the age.
Moreover, I can't avoid the thought that if we have weeds in the field (the world), there are some trying to infiltrate the ranks of the faithful in the local church. There is plenty of warning in the Scriptures against false teachers who set themselves against the teaching of the apostles and silently slip into the congregation to spread their teachings. Jesus' teaching to let the wheat and the weeds grow together applies to the world, but not to the church. The counsel of the apostles is that we must keep on eye on these wolves and keep them from harming the flock by whatever means: Membership classes, Supervision of the teachings, especially in Small Groups, and Church Discipline that includes excommunication.
Kingdom business is performed in a hostile environment. I may sit in a neat and tidy office, but spiritually I am in the depths of a battlefield. The battle is being waged on multiple fronts: relationships among brothers and sisters within the church, relationships with the world that surrounds us, and the dealings with wolves that step into the local church to harm it. How can I survive? The hope that Christ offers keeps me going. One day, I will shine like the sun in the kingdom of my Father.
Father, give me strength to stand firm until the end of times. Fill my heart with the hope of your return. Don't let my heart grow weary in the work of the harvest.