Daniel learned the language and literature of Babylon and became useful to the king. He also resolved not to defile himself (Daniel 1). Paul made tents (Acts 18:3). The text does not treat ordinary work or earning as the thing that places a person outside Christ. Jesus prays that the ones the Father has given him would be kept from the evil one while remaining in the world (John 17:15).
Being in the world includes the work that pays for food and tools. Being not of the world means that work does not become the source of identity. Genuine believers already belong to Christ. Once saved always saved. The security is not contingent on whether the job is labeled ministry. Fruit and cleaner motives are the right response to grace. They are not the condition that keeps a person in Christ.
I do secular work. I build projects. I am a sinner who still sins. I am not going to pretend the work makes me clean or that avoiding ordinary money makes me holier. Readers can examine the passages. They can disagree. The claim is that the text keeps location, work, and belonging distinct.