1 Peter 1:22 

 The Enduring Word
22 Since you have purified your souls in obeying the truth through the Spirit in sincere love of the brethren, love one another fervently with a pure heart,

3 John 4 

4 I have no greater joy than to hear that my children walk in truth.

2 Peter 2:20 

20 For if, after they have escaped the pollutions of the world through the knowledge of the Lord and Savior Jesus Christ, they are again entangled in them and overcome, the latter end is worse for them than the beginning.