The closer you are to the truth the greater your understanding. The nearer you are to the light the greater is your illumination.
God is the absolute Truth and God is the absolute Light. God as well is the absolute Liberty and the absolute Love. Being near to God is being infected and saturated at least relatively of God's truth, light, love and liberty.
The closer you are to the source of the stream of water the purer water you can drink. The farther you are, the farther the current, the greater the chances of impurities. The farther you are from the source of light the darker you have.
The Pope, Patriarchs, Archbishops and Bishops are believed to be closer and nearer to God hence they are titled Doctors of Divinity which can only mean but someone who attained greater understanding, comprehension and practice of virtues which the people can look up to to be always inspired and obedient. The fruits of the presence and indwelling of the Holy Spirit in them are evident, infectious and empowering.
With the fruits of the Holy Spirit the people will know if indeed they are as expected to be nearer and closer to the ultimate and absolute Truth and Light. By their fruits you shall know them.
However this does not apply to them alone but to all Christians and to all people of "good will" regardless which creed or religion they belong. The closer one to God he is godly. The closer one to Divinity he is divine. The closer one to Truth he is truth. The closer one to Light he is illuminating.