Verses with the word exercised in the New Testament (3 verses):

Hebrews 5:14
But strong meat belongeth to them that are of full age, even those who by reason of use have their senses exercised to discern both good and evil.

Hebrews 12:11
Now no chastening for the present seemeth to be joyous, but grievous: nevertheless afterward it yieldeth the peaceable fruit of righteousness unto them which are exercised thereby.

2 Peter 2:14
Having eyes full of adultery, and that cannot cease from sin; beguiling unstable souls: an heart they have exercised with covetous practices; cursed children: