The Bible to be the inspired, inerrant Word of God.
"For God so loved the world, that He gave His one and only Son, that whoever believes in Him shall not perish but have eternal life. For God did not send His Son into the world to condemn the world, but to save the world through Him." John 3:16-17
"For it is by grace that we are saved, through faith - and this not from yourselves, it is the gift of God - not by works, so that no one can boast." Ephesians 2:8-9
"He (Christ) was delivered over to death for our sins and was raised to life for our justification." Romans 4:25
"Therefore, if anyone is in Christ, he is a new creation; the old has gone, the new has come! All this is from God, who reconciled us to Himself through Christ and gave us the ministry of reconciliation: that God was reconciling the world to Himself in Christ, not counting men's sins against them. And He has committed to us the message of reconciliation." 2 Corinthians 5:17-19
"That we cannot by our own reason or strength believe in Jesus Christ our Lord, or come to Him; but the Holy Ghost has called us by the Gospel, enlightened us with His gifts, sanctified and keeps us in the true faith." (Apostle's Creed; III Article, Explanation - Dr. Martin Luther)
That God communicates all of the gifts of His grace to us through His Word (the Bible) and the Sacraments of Holy Baptism and the Lord's Supper.