Believing* is vital for a successful Christian life. Without believing we cannot please God. In Luke 18 is a parable teaching about believing.
1And he [Jesus] spake a parable unto them to this end, that man ought always to pray, and not to faint;
Here is the point of the parable, that men should continue praying and not grow weary.
2 Saying, There was in a city a judge, which feared not God, neither regarded man:
The judge is ungodly and elitist.
3 And there was a widow in that city; and she came unto him, saying, Avenge me of mine adversary.
The widow’s husband died requiring her to fend for herself. She says, “Avenge me of my adversary.” Avenge means to grant justice or legal protection from the person harassing her. The widow knew her legal rights and wanted the judge to exercise his authority on her behalf. The judge was not interested in helping her.
4 And he would not for a while: but afterward, he said within himself, Though I fear not God, nor regard man;
Even though he did not want to provide assistance because he did not care about her plight or the law.
5 Yet because of this widow troubleth me, I will avenge her, lest by her continual coming she weary me.
She continued disturbing the judge until he responded to her annoying behavior and not because of his concern for the law.
6 And the Lord said, Hear what the unjust judge saith.
The Lord calls the judge unjust, lawless.
7 And shall not God avenge his own elect, which cries day and night unto him, though he bears long with them?
8 I tell you that he will avenge them speedily. Nevertheless when the Son of man cometh, shall he find faith on the earth?
When Jesus returns, will he find believing on the earth? Find implies that Jesus will return looking for believers? Everybody believes. Believe what? The Bible, which is also called the Law.
Jesus will return looking for believers that are obedient to the Word of God. The widow asserted her legal right to the lawless judge to do judge righteously.
The parable reminds us that God is looking for believers that trust and obey the Bible. Believing entails persistence to continue praying and believing the specific verses until it comes to pass. If the prayer is not based on the bible then God has no obligation to answer.
* Both believe and faith are translated from the same word root. When it’s a noun (pistis) the translation is faith and a verb (pisteuo) is believe. This is one of the most confusing translation decisions in the Bible. I prefer believe and believing.