Yes. A Christian should always be just first. For example, a farmer would be unjust to give food to others if his own family is hungry. We need to fulfill our own responsibilities first. 1Timothy 5:8 (NIV), “Anyone who does not provide for their relatives, and especially for their own household, has denied the faith and is worse than an unbeliever.”
True kindness does not support sin. We would not give a ride to a fleeing bank robber to help him escape. Another example is based on the Apostle Paul’s words in 2 Thessalonians 3:10, “if any would not work neither should he eat.” Anyone who has the ability to work should take care of himself. If the person is a child, elderly or disabled, then we can help them. Even when our financial means are limited, we should at least offer kind and sympathetic words.
Was Jesus unkind when he overthrew the table of the moneychangers in the temple? Matthew 21:12,13 (NIV), “Jesus entered the temple courts and drove out all who were buying and selling there. He overturned the tables of the money changers and the benches of those selling doves. ‘It is written,’ he said to them, ‘My house will be called a house of prayer, but you are making it a den of robbers.’” No, the moneychangers were taking advantage of the people. Jesus, as God's representative, had to point it out. The Jews had covenanted to follow God's Law, and they were dishonoring God's arrangements.
We don’t behave based on our selfishness. We may not think, “I just don’t like them so I’m not going to be kind.” In the Old Testament, there are admonitions to assist our enemy’s donkey if it falls into a hole. (Deuteronomy 22:4) Withdrawing kindness doesn’t mean we are mean, revengeful or cruel. However, we may need to be more neutral. Wisdom and kindness may lead us to withdraw from some situations.
It takes prayer, wisdom, and patience to thoughtfully respond to a difficult situation. Ask God for guidance. “If any of you lacks wisdom, you should ask God, who gives generously to all without finding fault, and it will be given to you,” James 1:5. And remember: “Do not give evil for evil to any man. Let all your business be well ordered in the eyes of all men. As far as it is possible for you be at peace with all men,” Romans 12:17,18.