In the bracha before Shma we say "Ahava Rabba Ahavtanu" - Hashem, You love us so much. What is the expression of this love? That you gave us the Torah [the bracha continues talking about Torah]. Giving the Torah is an act of LOVE.
That is why the Torah says "Vishinantom livanecha" - You must teach your sons. Ideally, a father should teach his children because only he has sufficient love to enable him to convey the Torah properly.
Chazal expound "livanecha - ailu talmidecha" - Your sons means your students. A Rebbe must view his students as if they are his own sons, otherwise he cannot give over the Torah in its pristine form.
[Based on Maran HaRav Hutner ztz"l]
We should all merit having Rabbeim who love us and students whom we love!