I myself am convinced, my brothers and sisters, that you yourselves are full of goodness, filled with knowledge and competent to instruct one another. (NIV)
Personally I am satisfied about you, my brethren, that you yourselves are rich in goodness, amply filled with all [spiritual] knowledge and competent to admonish and counsel and instruct one another also. (AMP)
And I myself also am persuaded of you, my brethren, that ye also are full of goodness, filled with all knowledge, able also to admonish one another. (KJV)