What follows is a line of logic that may come in useful some day if you are challenged as to why it is not wrong to “proselytize.”
What is behind the prohibition of sharing one’s religious beliefs with another? If you were to ask someone who holds this position that “proselytism” should be prohibited, I can only think of two different ways that they could logically respond. 1) “Your religious belief is invalid, wrong, misguided, inaccurate (use whatever word you want) therefore it is unethical for you to share it with others since you are leading them astray. They must be protected from your wrong belief.” The other possibility would be, 2) “All religious beliefs are valid and therefore it is unethical of you to try to destroy another person’s valid belief system through the imposition of your belief system.
The answer to the first objection is as follows: If you see my religious beliefs as wrong and yours as right, then you have an ethical obligation to convince me and others of your beliefs. Ethically, you MUST try to proselytize me. If you are going to hold to a position that not all religious beliefs are valid, but some are, or maybe even only one is, then you must admit the ethical necessity of each religious system being allowed to present its claims. Freedom to “proselytize” is demanded by the position that there is only one or even a few belief systems that are valid.
Unrelated to this line of logic, but also a valid response to the first objection is the idea that what is true will ultimately prevail. This is Gamaliel’s argument in the book of Acts. “If this teaching is not of God, it will fail anyway, so let them “proselytize”. If it IS of God, then you will only find yourselves resisting God.”
In my thinking, the reponse to the second objection is even easier and much more obvious. If all religious beliefs are valid, then there should be absolutely no ethical objection to allowing each individual to choose whatever valid religious belief he so chooses. Obviously this would not include a coerced change of beliefs, but although often accused of coercion, no truly Christian evangelism even comes close to this.
I realize that pure logic will never lead to religious freedom to share one’s religious beliefs because there is an active spiritual resistance to God’s rule behind all prohibitions of religious freedom, but the above arguments might be useful at some point.