I try (everything is progress towards a known unreachable ideal character) to live a righteous life while believing in God and the Day of Judgment with excitement, not fear (whilst still keeping in mind my share of this world). In Kierkegaard’s terms: I’ve left the aesthetic stage, walked through the ethical stage and I leapt into the religious stage, and God caught me. Once you do that, I’ve found that the rest comes by itself, and your fulfilment is mostly guaranteed (this is still just my personal experience though).