Here is some advice from Charles Spurgeon to those who want to see sinners saved:
Impressed with a sense of their danger, give the ungodly no rest in their sins; knock again and again at the door of their hearts, and knock as for life and death. Your solicitude, your earnestness, your anxiety, your travailing in birth for them God will bless to their arousing. God works mightily by this instrumentality. But our agony of soul must be real and not feigned, and therefore our hearts must be brought into true sympathy with God. Low piety means low spiritual power.
I see a number of important truths here if we want to be effective in advancing God’s Kingdom. First, we must genuinely care about lost sinners. Second, we must share the truth about sin and judgment with them. We can’t sit idly by and allow them to continue in sin unchallenged and unwarned. Third, we must be persistent. We must continue to pray, continue to care, continue to share the truth of God’s Word. We should not expect genuine conversion to be a quick, easy process!
Pastor Mike Walters
Source: Ian Murray, The Old Evangelicalism, p.63