There are numerous traps we who believe in salvation by grace can fall into, and Paul repeatedly pointed them out. One is the notion that since I am saved now and forever I can live for myself (flesh) without any negative impact on my life.
Paul warned that a person who lives for self (sows to the flesh) will “reap corruption.” 6:8 The word translated corruption means “subject to decay”. In other words, when I spend my time, money, and energy for myself everything I gain will decay away. I've jumped onto the short-tracked roller-coaster of the economics of scarcity in a decaying world.
In contrast the Apostle said that a person who lives for God (sows to the Spirit) will reap “life everlasting.” 6:8 Everlasting means “without end.” So… the apostle argued that spending my life for God’s work has everlasting benefits. In other words, when I spend my time, money, and energy for God everything I gain will last forever. In a sense my eternal day starts here and now. I've stepped into an economy of supply in an existence that lasts forever.
It makes sense to be eagerly involved in God's work. To be involved in God’s economy is to transcend this world’s system. God’s work and His government will never fail. Wow... we get heaven, everlasting life, and a life on this earth that counts. God's Grace is amazing.