Who said this?

IIAce

I was listening to a sermon by Bishop Youssef and in it he mentioned that a Russian father said/wrote that to make the whole life holy, it is enough to only make the present moment holy. i.e. if one makes sure that the the moment he/she is living in is holy, then the whole life will be holy. Similarly, if one does not make the present moment holy then the whole life will not be holy. This is because the "present moment" is really all we can control...not the past and not the future, but we always have control over the present moment.

Does anyone know who the person who talked or wrote about this was? If I remember correctly, Bishop Youssef said he was Russian, but I am not sure if it was a Russian clergy person or not.

Thanks!