Luke 14:28-30, 33

For which one of you, when he wants to build a watchtower [for his guards], does not first sit down and calculate the cost, to see if he has enough to finish it? Otherwise, when he has laid a foundation and is unable to finish [the building], all who see it will begin to ridicule him, saying, ‘This man began to build and was not able to finish!’

So then, none of you can be My disciple who does not [carefully consider the cost and then for My sake] give up all his own possessions.