Holiness in the lives of professing believers in Christ has a powerful influence upon the ungodly world around them. One of the reasons why on some occasions many come to faith in Christ, while on others few, is down to the holiness or lack of it in professing believers in Christ.
Justin Martyr a leading figure in church history, on coming to faith in Christ said, "The holiness which shined in Christian's lives, that triumphed over the cruelty of their persecutors who put them to death, made me conclude the doctrine of the gospel was truth."
It is hardly surprising in these times of moral and spiritual decay, when so many professing believers in Christ live careless and worldly lives, we see few coming to faith in Christ. A holy life is a God honouring life before an ungodly world. In Titus 2 v 8 it says how holy speech silences the ungodly, as they have no evil thing to say about you. We are told in 1 Peter 2 v 15, "For so is the will of God, that with well doing ye may put to silence the ignorance of foolish men." We are also told in 1 Peter 2 v 9 that a holy life will make known the praises of God, who called us out of the spiritual darkness we were in.
People say I don't believe there is a God when there is suffering like Auschwitz and this coronavirus in the world. However, if as a professing believer in Christ you live a holy life, they may say I believe there is a God for I have seen Him in your life!