1 Cor. 10:31 - So whether you eat or drink or whatever you do, do it all for the glory of God.
Time spent on anything not glorifying God
Prov. 22:29 - Do you see a man skilled in his work? He will serve before kings; he will not serve before obscure men.
Projects pursued outside of our calling
Matthew 6:20; 16:18 - But store up for yourselves treasures in heaven, where moth and rust do not destroy, and where thieves do not break in and steal; I will build my church, and the gates of Hades will not overcome it. I will give you the keys of the kingdom of heaven; whatever you bind on earth will be bound in heaven, and whatever you loose on earth will be loosed in heaven.
Money spent that does not most effectively build the church.
Proverbs 15:1-2, 4 -- Who may live on your holy hill? He whose walk is blameless and who does what is righteous, who speaks the truth from his heart.... who keeps his oath even when it hurts