God wants you "to make your call and election sure, for if you do these things you will never stumble" (2 Peter 1:10). That means you are to grow in your faith, in the grace and knowledge of our Lord Jesus Christ (2 Peter 3:18). Your call and election includes your responsibility to believe the gospel of Christ (1 Corinthians 15:1-4). Thereafter, you grow spiritually with the assurance of faith.
Knowledge of this world comes from observation of things that are seen. It is the knowledge of science. There is another kind of knowledge. It is based upon revelation. It is the knowledge of faith. "Now faith is the substance of things hoped for, the evidence of things not seen" (Hebrews 11:1). This is the knowledge of God. It is knowledge revealed by the Holy Spirit, through the prophets and the apostles.
To those who don't believe Christ died for their sins, the cross is meaningless as far as life today. It's simply something that happened to a man centuries ago. To you who believe, Christ crucified is the power of God unto salvation.
William Reid wrote, "In all true prayer, great stress should be laid on the blood of Jesus. Perhaps, no evidence distinguishes a declension in the power and spirituality of prayer more strongly than an overlooking of this. Where the atoning blood is kept out of view, not recognized, not pleaded, not made the grand plea, there is a deficiency of power in prayer."
Many things happen in this life that we simply do not understand. Why? That's the question when tragedy, heartache, and trouble comes our way. The imagination takes us into many false and foolish ideas. However, faith will always bring you to God. When doubts assail you and unbelief threatens you, faith knows a sure refuge in God.