On hearing this, Jesus said to them, "It is not the healthy who need a doctor, but the sick. I have not come to call the righteous, but sinners." Mark 2:17
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This verse speaks to repentant sinners, those who wish to learn and live the righteous way.
Having said that, If a priest is a homosexual, he must be the sort that acknowledges the burden of his SIN, stay in prayer and not practice deviancy clearly shown as against G-d and nature.
Being human, we all sin in many ways. We also may have the propensity towards particular sins due to heredity and/or environment. It is in confession and a willingness to follow Christ that forgives the sin.
Unless I am mistaken Jesus was speaking to his disciples and answering a question raised by the Pharisees.
16 When the scribes of the Pharisees saw that He was eating with the sinners and tax collectors, they said to His disciples, “Why is He eating and drinking with tax collectors and sinners?” 17 And hearing this, Jesus said to them, “It is not those who are healthy who need a physician, but those who are sick; I did not come to call the righteous, but sinners.” Mark 2:16-17
I am not diminishing the importance of confession and repentance. I am merely trying to point out that as long as Christians find insulting homosexuals to be some kind of sport, there will not be much much opportunity to share the Gospel with them. (For the record, the unclear reference in the previous sentence is intentional.)