Public witnessing is one excellent method of spreading the good news. Many Witnesses are having a very effective and rewarding share in such work.
إِذَا كُنْتَ تَسْتَصْعِبُ ٱلشَّهَادَةَ ٱلْعَلَنِيَّةَ ،‏ فَلَا تَسْتَسْلِمْ .‏