Every ounce of blood, sweat, and tears that you put into a relationship here on this earth is ALWAYS WORTH IT, PERIOD. There will be no regret in investing in people. Though not all people will be with us in Heaven, it does not make the time spent loving them, living life with them, or sacrificing for them a mistake. Just like Jesus death for all humanity on the cross was not a mistake, even though many will reject him eternally, the sacrifice brings glory to God's love.