God has promised to look after our needs. Why would an obedient believer find himself/herself out of a job or lonely?

While God promises to provide for the needs of the believers, God does not promise that believers will have an easy life. There is no promise from God for health and wealth and other false expectations. Even believers who are focusing on heavenly things can still lose jobs and be single even though they desire to be married. Believers can go through sufferings that are totally unrelated to divine discipline. Spiritual leaders can get sick, die young, have accidents, etc. and this may not have anything to do with divine discipline but with bringing believers to maturity. Situations like loneliness and being out of a job can be eased by being in fellowship with other believers and by being willing to take jobs that may not be what one prefers. God promises to meet our needs and not our wants.