Is it wrong for a Christian to have material things?
No, it is not wrong for a Christian to have material things, provided priorities are right. If material things become more important than spiritual things, then it is wrong. God may bless believers with things in grace, but they cannot be demanded, and they must remain in the right order of priority.
Les explains from Colossians 3:1-2 that believers are to seek things above and set their affection on things above, not on things on the earth. He notes there is nothing wrong with things if our priorities are right. If things are more important than spiritual things, then it is wrong. But if spiritual priorities are where they belong, then all these things can be added. God is not tight, but we cannot demand them of Him. If He sees fit in grace to bless us with things, there is nothing wrong as long as they are in the right order of priority. This is written to believers, who are dead with Christ.