God doesn't promise us success. On the contrary, as Paul said,

(2 Corinthians 11:24-28 NIV) Five times I received from the Jews the forty lashes minus one. {25} Three times I was beaten with rods, once I was stoned, three times I was shipwrecked, I spent a night and a day in the open sea, {26} I have been constantly on the move. I have been in danger from rivers, in danger from bandits, in danger from my own countrymen, in danger from Gentiles; in danger in the city, in danger in the country, in danger at sea; and in danger from false brothers. {27} I have labored and toiled and have often gone without sleep; I have known hunger and thirst and have often gone without food; I have been cold and naked. {28} Besides everything else, I face daily the pressure of my concern for all the churches.