One who loves the Lord will love the truth of the Lord. That is the acid test. Love means that one will try and do what pleases one whom one loves. The point is, one will be found trying to please Christ if one loves Him. When Jesus chose His apostles and sent them out to teach His will to their fellow Jew and later to us Gentiles, He warned them that they were not going to have it easy.
Truth often demands change.
Change demands sacrifices. Not all men are willing to make either the needed changes nor sacrifices which truth demands and so will become upset with the one teaching them, as Jesus said above. Truth is narrow and restrictive. Only few will find it. If not, you and I can change that by a greater love of the truth and of our Lord and by giving more time to a study and a prayerful consideration of what is really important in our lives.