Berean Study Bible
Finally, be strong in the Lord and in His mighty power.

King James Bible
Finally, my brethren, be strong in the Lord, and in the power of his might.

American Standard Version
Finally, be strong in the Lord, and in the strength of his might.

Darby Bible Translation
For the rest, brethren, be strong in [the] Lord, and in the might of his strength.

Douay-Rheims Bible
Finally, brethren, be strengthened in the Lord, and in the might of his power.

English Revised Version
Finally, be strong in the Lord, and in the strength of his might.

Young's Literal Translation
As to the rest, my brethren, be strong in the Lord, and in the power of his might;