By way of counseling, what would you say to a young teenager who "sometimes feels weak" because he lost his mum?
Life is filled with difficulties. You can either let them overwhelm you or you can overcome them. God allows Satan to bring difficulties into our lives because people can rise to the challenge and become better people for enduring through them.
"And you have forgotten the exhortation which speaks to you as to sons: "My son, do not despise the chastening of the LORD, Nor be discouraged when you are rebuked by Him; For whom the LORD loves He chastens, And scourges every son whom He receives." If you endure chastening, God deals with you as with sons; for what son is there whom a father does not chasten? But if you are without chastening, of which all have become partakers, then you are illegitimate and not sons. Furthermore, we have had human fathers who corrected us, and we paid them respect. Shall we not much more readily be in subjection to the Father of spirits and live? For they indeed for a few days chastened us as seemed best to them, but He for our profit, that we may be partakers of His holiness. Now no chastening seems to be joyful for the present, but painful; nevertheless, afterward it yields the peaceable fruit of righteousness to those who have been trained by it. Therefore strengthen the hands which hang down, and the feeble knees, and make straight paths for your feet, so that what is lame may not be dislocated, but rather be healed. Pursue peace with all people, and holiness, without which no one will see the Lord: looking carefully lest anyone fall short of the grace of God; lest any root of bitterness springing up cause trouble, and by this many become defiled" (Hebrews 12:5-15).
To admit that the way is hard at times is reasonable, but don't give up.
Thank you. That was exactly what I told him. Your email has just given me insight, that is, to send him a book of encouragement.