I may not run in vain

Sometimes even young people have spiritual struggles. This happens when they do not see fruitfulness or encounter numerous frustrations or opposition. One was wondering the website he developed for evangelism and teaching was right as his pastor trashed it. Indeed, it was excellent. Another young man wanted to go in obedience to the Lord to another nation, pastor vetoed him stating he was needed more in the local church. (Funny as Church at Antioch had to send two of the five leaders as missionaries Acts 13:1,2) His struggle was to disobey pastor or God; at last heeding to wise counsel of a friend went to mission field. Even John the Baptist had a question of doubt about Messiah, even though he identified Him to the Nation of Israel. (Matthew 11:3)
Paul had a great successful ministry among non-Jews. The Jewish Christians were harassing him by a whisper campaign (like trolls in social media) that Paul was not teaching the right gospel, circumcision was nullified and was against Temple, Law and Judaism. Paul writes his agony and his trip to Jerusalem: “ I went up because of a revelation and set before them (though privately before those who seemed influential) the gospel that I proclaim among the Gentiles, in order to make sure I was not running or had not run in vain.” James, Cephas and John who were pillars of the early church discerned the grace given to Paul and gave his ‘right hand of fellowship.’ (Galatians 2: 2, 9)
Elijah thought he was alone, only one believer in the whole Nation of Israel. Lord had to remind him that there are seven thousand who did not compromise. (I Kings 19:10,18)
When we walk through Valleys of doubt, let us walk in faith and not in sight with his promises. (Psalms 121:3) Yet God is gracious to send helps to affirm that we are in right path through Visions or ordering circumstances or His Word, His Spirit or His people.
Do I run in such a way to win? (I Corinthians 9:24)