True wisdom is forged in fires of community. Those who seek wisdom need God and prayer, no doubt. But the normal context in which God answers his people's prayers for wisdom isn't solitude but relationships.
This quote is just another reminder to me that I need counsel from people that are interested in my growth as a disciple. I tend to listen and accept words that are easy on my ears and my ego. But pride often causes met to question the insight of those who do not agree with my assessment of myself. When I wander into a place where I believe I am the best judge of my motives and words, I have left the path of sanctification. I tend to cut myself a lot of slack in areas where discipline and correction is required.
That is why I am grateful for guys like John and Doug in my small group at church. They are guys who are pursuing holiness and are not afraid to call me out when I choose to underestimate or ignore sin in my life. (I actually typed "wife" there. That would have been really bad.) I need that type of accountability that goes beyond leveling an accurate judgement to applying grace. God has been good to me.