"Though I am free and belong to no man, I make myself a slave to everyone, to win as many as possible!! To the Jews I became like a Jew, to win the Jews. To those under the law I became like one under the law (though I myself am not under ...the law), so as to win those under the law.
To those not having the law I became like one not having the law (though I am not free from God's law but am under Christ's law), so as to win those not having the law. To the weak I became weak, to win the weak. I have become all things to all men so that by all possible means I might save some. I do all this for the sake of the gospel, that I may share in its blessings." 1 Cor 9:19-23

I have heard it said that tactfulness in ministry is not important, only truthfulness.  Although I believe that no truth should ever be denied for the sake of how it will be received, the delivery of truth is very important.  I wonder how many people can be brought to Jesus if they are offended at the offset of a conversation.  After an offense, most people stop listening.  Tactfulness in conversation is the what you get when you take all the love out of it.  It's like rice with no salt or butter, yuck!  Paul tells us in the scriptures that it is important for us to bring ourselves into slavery to those whom we are ministering to for the sake of the integrity of the Gospel and of reaching the lost.  Paul realized also that he was free and that he belonged to no man, however he made the choice himself to bring his actions and words under slavery to everyone he met so that he might win them for Jesus.  This is a true act of being selfless and putting one's calling before ones own fleshly desires in ministry and I believe that when we follow in this very wise example that Paul gives us we will find that more people will listen to us and respect us as ministers and be brought into the Kingdom fold.  God forces no one to love Him, neither should we act in an overbearing manner when ministering or even apologizing our faith.  There should never ever come a time that we debate and argue our faith with others, but only give answers to those who are truly seeking answers and to have sensible and always edifying conversation about God's Word.  When we start to argue then the old evil sin of pride has slipped into the conversation on one side or the other and there will be no good fruit from it.  It would be better to cut that tongue off than to let it wag.  (Metaphorically speaking of course) So let's not call things sinful that aren't sin to start with and remember that we are free from the law in Christ Jesus, however, even though we are owned by no man, we are expected to obediently temper our actions as Christ Jesus has taught us to do.  Jesus said that if we love Him then keep His commandments.  His commandments were simple: Love God with all that we are and love our neighbors with the same respect we expect for ourselves from others.  When we love others this way, we will put their needs first, before our own.  Let us remember that our demeanor, as Christians, matters and that what we do for the Lord is not about us, but about Christ and the Kingdom of God.