Our efforts are in vain if we are able to capture people's interest and win their approval, but God does not acknowledge or reward us.
In our relationship with God, obedience to God's will puts us in check. We might not need to do much most of the time. Even though obedience is minimal, giving it to God exalts Him. The foundation of the Christian faith is obedience.
Since salvation entails giving everything to God and letting Him take control of our life, we should doubt our salvation if we find it difficult to obey.