From a mustard seed to the Tree of Life
One human being can not compel another to believe in God no matter what arguments are used nor how compelling they might be, for we have all been paid the ultimate compliment of the gift of freewill by God to decide for ourselves.
From the tiniest notion of faith, untold mysteries can unfold and so when someone hears about Christ and that initial thought takes root then it is explained in parables, how, with God's help, through prayer and scripture, we can become ever firmer in faith and in our understanding of His Kingdom. In Luke's Gospel 13: 18-19 we are told by Christ that: “The kingdom of heaven is like a mustard seed that a man planted in his field and whilst it is the smallest of all seeds, yet it grows into the largest of garden plants and becomes a tree, so that the birds of the air come and nest in its branches.”
He also told us in Luke's Gospel 13: 20-21 that: “The kingdom of heaven is like yeast that a woman took and mixed into three measures of flour, until all of it was leavened.”
Those two parables reveal to us how a knowledge of God's Kingdom is first planted as a notion in our mind and then, if the soil of our mind is receptive and sufficiently fertile, it will germinate and continue to grow. Once started it will, providing it is fed and watered with Prayer and Scripture, continue until the death of the human life it inhabits which then gains entrance into the reality of God's Kingdom.
However, in Matthew's Gospel 13: 12. it is also explained that “To those who listen to my teaching, more understanding will be given, and they will have an abundance of knowledge; but to those who are not listening, even what little understanding they have will be taken away from them.”