Brothers, do not be children in your understanding; rather, in malice be children, but in understanding be men. (1 Corinthians 14:20, EMTV).
Understanding. The Greek word φρήν
phren means the diaphragm area of the body referring to not only the anatomy but the source of feeling, emotions, etc. By extension it means thinking, understanding, mind, etc. Probably the best word for today would be sympathy. The understanding would be when someone listens to another and states, "O, now I understand" being used in sympathetic situation.
Malice is the hate of heart, mind, and actions.
What the apostle (under inspiration) is telling us that there is a contrast between sympathy and malice. We are to be like children regarding malice and sympathy as adults. We are to lay aside malice, be ignorant of it, and not be an expert in it. We are to grab hold of sympathy, be well acquainted with it, and be an expert in it. This God does for us, and we need to do for others.
The hate and death culture that is all too common today is not to be the culture of the Christian.