The real definition of success from spiritual perspective is when one is able to seek the essence and see the hand of God in every situation.
Every failure contains a seed of success.
Absorb ourselves in the supreme of all prayers, the Hare Krishna Maha Mantra, fix our mind begging for service and begging for the power to please the Lord by our service, because in essence the success of our service is how we please Krishna.
To achieve success in our lives, we need strength beyond ourselves and association of sincere souls. We also need to resolve to take shelter of the holy names of God and soberly remember that today we are one year closer to death. At the same time we need to meditate on our purpose in life and that will guarantee an eternal life, beyond the temporary existence of this world.