Knowledge

amanitvam adambhitvam,ahimsa ksantir arjavam
acharyopasanam saucam,sithairyam atmavinigraham.--7
Humility[absence of pride],integrity[absence of deceit],non-violence,patience,uprightness,service of the teacher,purity[of body and mind],steadfastness and self control.
these are main factors illegibility for knowledge.
Humility[absence of pride]--Gita teaches to avoid living with such vanity.every type of wars, quarrel, disputes,comes from it.you can see destruction from centuries by ego.you can see Hitlers,Changez khans,Alexenders,comes from it.Quarrel in a street and in a home,it may be in husband and wife or dad and son .The root cause of this is our ego.So our saints,it may be Jesus,Nanak,Krishana,they all tried to escape us from it.
Void of vanity[absence of deceit]--We always try to show people this and that.I am superior of all.I have a lot of money or property.I have a lot of knowledge.I am wise.We all wants to sit on the upper level of the ladder.
Non violence