The sabbath law includes a command to work six days a week (Ex 20:9), so we should be looking to be productive every day except Saturday.
Working is therefore good for us on every other day, even if we live in a culture mistaking Sunday for sabbath, unless we’re causing weaker saints to stumble, to violate what they mistake to be the sabbath, thus wounding their conscience. (1Co 8:12) In that case we might need to be discrete about it; if we’re a bit creative we can likely figure out a way to worship and fellowship with others and also get some work done on Sunday, resting on Saturday as God commands.
We know work is good because God is good, He designed us to work before the Fall (Ge 2:15), and He proclaimed it to be good. (Ge 1:31)
We can also see in this command that God has a particular job for each one of us: He says, “do all thy work.” There is work that is ours, and work that is not. A large part of being successful in life is figuring out what we’re designed for, finding our calling, identifying the work God has given each of us uniquely to do. It is then that we can apply ourselves, training, equipping, disciplining and preparing ourselves (2Ti_2:21), honing our skills and talents to serve Him with confidence and joy, trusting Him for strength to overcome, and to accomplish (2Co 9:8) what He’s granted us to do. (Eph 6:6)
When we’re living according to our design, obeying and honoring God as well as we can, we’re free, satisfied as we fulfill our purpose, complete in Him. (Col 2:10) It is here that we find meaning and fulfillment. (Php 1:21)
Day after day, as we prayerfully seek to labor for our Lord, working as unto Him (Col 3:23-24), we pursue our destiny: to hear, “Well done, good and faithful servant.” (Mt 25:23) There is no higher calling than to please the One Who made us. (Col 1:10)