Is it to help them develop a strong prayer life, or a disciplined pattern of Scripture memory? Or to be a faithful witness to the lost? Very possibly, but…
Infinitely more basic is to help them form rock-ribbed convictions in three fundamental areas (1 Corinthians 13:13):
FAITH — Does your “disciple” believe God?
Does he (or she) demonstrate faith in God by a willingness to lay it on the line when the chips are down, even to the point of climbing into the fiery furnace (so to speak), as did Shadrach, Meshach and Abednego? (Daniel 3) Does your disciple authenticate his faith by demonstrating congruency of life between the secular and the spiritual? (Psalm 24:3, 4)
“Without faith it is impossible to please God, because anyone who comes to him must believe that he exists and that he rewards those who earnestly seek him… The work of God is this: to believe in the One He has sent.” (Hebrews 11:6; John 6:29)
HOPE — Does your disciple have a “Pilgrim Mentality”?
Is his primary focus on the temporal or on the eternal? Does he, by his life demonstrate the fact that he understands the transitory nature of our earthly existence, and the importance of investing in the eternal?
“These all died in faith, not having received the promises, but having seen them afar off were assured of them, embraced them and confessed that they were strangers and pilgrims on the earth… looking for a country of their own… longing for a better country—a heavenly one… ” (Hebrews 11:13-16-nkjv)
LOVE — Does your disciple live a life of selfless sacrifice?
Has he been so impacted by Christ’s love that he is compelled to live a life of loving service rather than selfish indulgence?
“For Christ‘s love compels us… that those who live should no longer live for themselves but for Him who died for them and was raised again.” (2 Corinthians 5:14, 15)
By the way, you and I both know that the way you build these qualities into the life of another is by modeling them first in your own life.