Berean Standard Bible (BSB)
Brothers, stop thinking like children. In regard to evil be infants, but in your thinking be mature.
World English Bible (WEB)
Brothers, don’t be children in thoughts, yet in malice be babies, but in thoughts be mature.
Strong's King James
Brethren{G80}, be{G1096}{(G5737)} not{G3361} children{G3813} in understanding{G5424}: howbeit{G235} in malice{G2549} be ye children{G3515}{(G5720)}, but{G1161} in understanding{G5424} be{G1096}{(G5737)} men{G5046}.
The F.O.G *
(20) Brothers, don't be children in your thinking, yet in evil be infants. In your thinking be mature.
The F.O.G Message *
Young's Literal Translation
Brethren, become not children in the understanding, but in the evil be ye babes, and in the understanding become ye perfect;