Faith and doubt go hand in hand. Spanish philosopher Miguel de Unamuno once famously said: "Those who believe that they believe in God, but without passion in their hearts, without anguish in mind, without uncertainty, without doubt, without an element of despair even in their consolation, believe in the God idea, not God himself."

In his book Know Doubt: The Importance of Embracing Uncertainty in Your Faith, John Ortberg says that there is "a mystery to faith, as there is to life, that I don't fully understand", and argues that faith and doubt can – and do – exist alongside one another.

"When we take seriously the reality of faith and doubt, the most important word in the phrase is the one in the middle," he writes. "Because most people I know are a mix of the two."

In fact, Ortberg argues, "When people of faith and not willing to sit quietly sometimes and let doubt make its case, bad things can happen."

It's important to wrestle with our questions and doubts – check the Psalms for a biblical example of that. But it's also vital to remember that God is faithful, even when we're not sure of him. Here are 10 Bible verses to remind you of his goodness:

Romans 8:24-30

"For in this hope we were saved. But hope that is seen is no hope at all. Who hopes for what they already have? But if we hope for what we do not yet have, we wait for it patiently.In the same way, the Spirit helps us in our weakness. We do not know what we ought to pray for, but the Spirit himself intercedes for us through wordless groans. And he who searches our hearts knows the mind of the Spirit, because the Spirit intercedes for God's people in accordance with the will of God. And we know that in all things God works for the good of those who love him, who have been called according to his purpose. For those God foreknew he also predestined to be conformed to the image of his Son, that he might be the firstborn among many brothers and sisters.And those he predestined, he also called; those he called, he also justified; those he justified, he also glorified."

2 Corinthians 12:9-10

"But he said to me, 'My grace is sufficient for you, for my power is made perfect in weakness.' Therefore I will boast all the more gladly about my weaknesses, so that Christ's power may rest on me.That is why, for Christ's sake, I delight in weaknesses, in insults, in hardships, in persecutions, in difficulties. For when I am weak, then I am strong."

Lamentations 3: 22-24

"Because of the Lord's great love we are not consumed, for his compassions never fail. They are new every morning; great is your faithfulness. I say to myself, 'The Lord is my portion; therefore I will wait for him.'"

Romans 4:18-21

"Against all hope, Abraham in hope believed and so became the father of many nations, just as it had been said to him, 'So shall your offspring be.' Without weakening in his faith, he faced the fact that his body was as good as dead – since he was about a hundred years old – and that Sarah's womb was also dead.Yet he did not waver through unbelief regarding the promise of God, but was strengthened in his faith and gave glory to God, being fully persuaded that God had power to do what he had promised."

Ephesians 3:20-21

"Now to him who is able to do immeasurably more than all we ask or imagine, according to his power that is at work within us,to him be glory in the church and in Christ Jesus throughout all generations, for ever and ever! Amen."

1 Thessalonians 5:23-24

"May God himself, the God of peace, sanctify you through and through. May your whole spirit, soul and body be kept blameless at the coming of our Lord Jesus Christ.The one who calls you is faithful, and he will do it."

Hebrews 10:19-23

"Therefore, brothers and sisters, since we have confidence to enter the Most Holy Place by the blood of Jesus,by a new and living way opened for us through the curtain, that is, his body,and since we have a great priest over the house of God, let us draw near to God with a sincere heart and with the full assurance that faith brings, having our hearts sprinkled to cleanse us from a guilty conscience and having our bodies washed with pure water. Let us hold unswervingly to the hope we profess, for he who promised is faithful."

Deuteronomy 7:9

"Know therefore that the Lord your God is God; he is the faithful God, keeping his covenant of love to a thousand generations of those who love him and keep his commandments."

Psalm 61:1-5

"Hear my cry, O God; listen to my prayer.From the ends of the earth I call to you, I call as my heart grows faint; lead me to the rock that is higher than I. For you have been my refuge, a strong tower against the foe.I long to dwell in your tent forever and take refuge in the shelter of your wings. For you, God, have heard my vows; you have given me the heritage of those who fear your name."

Psalm 73:23-26

"Yet I am always with you; you hold me by my right hand.You guide me with your counsel, and afterward you will take me into glory.Whom have I in heaven but you? And earth has nothing I desire besides you.My flesh and my heart may fail, but God is the strength of my heart and my portion forever."