crown of righteousness: being declared righteous at the time of judgment was the only thing that remained for Paul (see also James 1:12; 1 Peter 5:4; Revelation 2:10; 3:11).
If we live expecting that Christ will return, we will eagerly look forward to His appearing to establish his kingdom (see 1 Timothy 6:14; 2 Timothy 4:1). If we do not follow Christ’s commands, we will not welcome his appearing, because it will be as Judge.