The stronger our convictions (if they are faithful to the truth of Scripture), the more gentle and tender-hearted we will tend to be.
"The servant of the Lord must not strive; but be gentle unto all men, apt to teach, patient, in meekness instructing those that oppose themselves" (II Timothy 2:24-26).
Not only is it possible to make a forthright and confident stand for Truth without harshness or rancor. It is required. The Holy Spirit who leads and enables us fosters not only Christ's light in us, but also Christ's attitude. Indeed, we can be correct in our doctrinal content, but if our demeanor and attitude are wrong, we are wrong. Born again believers are not engaged in spiritual battle to win arguments, but rather to present the spirit and truth of Christ in a manner whereby hearts are directly confronted by His living Person. Such expression will involve both what we affirm, and how we affirm it.
The Lord Jesus and His apostles were often pointedly straightforward, especially toward those whose spiritually arrogant and harsh attitudes betrayed not only the doctrine of truth, but also its demeanor. The norm, however, is gentleness, and we must always remember that the power of the Christian gospel is its cross as well as its resurrection. As our words, attitudes, and demeanor reflect the Lord whose sublime character made Him the Lamb of Calvary, the power of such love will bear strong witness to the truth. Our own faces and words will fade from the attention of our hearer, and the Lord Jesus will present Himself to the hearts of those who will hear and receive Him.
"When He was reviled, reviled not again; when He suffered, He threatened not; but committed Himself to Him that judgeth righteously."
(I Peter 2:23)