So you want to know the best time to serve the Lord? It is the present time, which is in your possession here and now. The past is no longer yours; the future has not come yet and is uncertain. The best time is really the present, which you should spend in serving God. If you want to recover lost time, do your best, with fervor and diligence, in the time that still remains to you.
(Sermons 16; O. IX, p. 132)