You’re wise to be sensitive to your brother’s apparent interest in spiritual things, even if it’s shallow right now or taking a direction that might not be best. Jesus solemnly warned, “If anyone causes one of these little ones who believe in me to sin, it would be better for him to be thrown into the sea” (Mark 9:42).
My first suggestion is that you do everything you can to encourage your brother to grow in his faith. Perhaps the place to start is to ask him why this particular program interests him. Is he simply attracted to it because it appeals to his selfish desires — namely, a desire to get rich? Or is something deeper going on in his life — namely, a hunger for God?
Then encourage him to read the Bible and learn more about God and His will for our lives. Encourage him especially to focus on the Gospels of the New Testament, because they will bring him into direct contact with Jesus, who alone is our Savior. Most of all, encourage him to commit his life to Jesus and make Him the center of his life.
Pray for your brother also, asking God to create within him a desire to live for Christ every day. And pray for yourself, as well, that God will help you encourage him to walk with Jesus every day.