Paul urged Timothy to remember that real "gain" comes from the acquisition of true godliness that includes an attitude of contentment with one"s material possessions. It does not come from teaching godliness to others primarily to receive pay for doing so. That conduct demonstrates an attitude of discontent with one"s material possessions. [source][source][source]
The apostle further reminded Timothy that there is really no relationship between godliness and one"s material possessions. Material things are transitory. As we entered the world without any, so we shall leave it (cf. Job 1:21; Ecclesiastes 5:15). Possessions are simply tools we can use to bring glory to God (cf. 1 Timothy 4:3-4; 1 Timothy 6:17). Having the basic necessities of life, food and clothing, we can and should be content (cf. Matthew 6:24-34; Luke 12:16-32; Hebrews 13:5-6). Food and clothing are a synecdoche for all the necessities of life. Paul had learned this lesson of healthy detachment from material things in his own life ( Philippians 4:10-13). We must learn it too. [source][source][source]
"Materialism is a desire to possess things instead of a love for the God who made those things." [1][source]
"Contentment is one of the greatest assets of life." [2][source]
"How can the Christian learn to be content with simple living? Certainly not by accepting the standards set by this world. Paul suggests that an eternal perspective and an attitude of detachment toward things are prerequisites. As an eternal perspective develops, dependence on things material will decline." [3][source]