God presented Christ as a sacrifice of atonement, through the shedding of his blood—to be received by faith. He did this to demonstrate his righteousness, because in his forbearance he had left the sins committed beforehand unpunished—
Romans 3:25 NIV
We all have opinions, and while convinced they are correct, the reasonable person also willingly accepts opposing viewpoints. Some wiggle room in our thinking allows us to admit that some of our opinions may be false. We also have things we believe. Belief is more substantial than opinions, but it may not hold up to scrutiny. For example, I may believe Elvis is working at 7-11, but no facts support our belief. On the other hand, faith is something we hold with certainty; it's a personal conviction that while we may not fully comprehend the how of something, we know it is true.
As Christians, we accept by faith that Jesus Christ is the Son of God, sent to die for our sins, and by his blood, we are redeemed. The validity of our belief is based on the supporting evidence provided in scripture. God created man, man sinned, and God ultimately sent Jesus to heal the rift created by sin. While we weren't there to witness the historical accuracy of scripture, we accept its truth.
Perhaps, more importantly, we know it's true because we have personal knowledge. We have first-hand encounters with God's grace and have witnessed the Spirit moving in our lives. We have noted the difference between our lives before and after accepting Christ as our Savior. So, while we don't completely understand God's love and grace, it's not something tangible to be weighed and measured; we know it to be true.
God, we thank you for your grace and love in sending Jesus Christ. By our faith in his sacrifice for our sins, we are healed. We also thank you for the Holy Spirit, which demonstrates your compassion for us. Yet, despite all the proof of your love, our faith falters, and we allow doubt to creep in. We also confess we entertain opinions and beliefs counter to your righteousness. Forgive us those times, that we may remember and be renewed, and our hearts be made right. In the name of our Savior, Jesus Christ, we pray. Amen.