The following is a summary of the Bible's teaching, expanded further in the Westminster Confession of Faith and Catechisms.
The Bible
The Bible is the infallible and inerrant Word of God, breathed out (inspired) by His Holy Spirit.The Bible was written by chosen fallible men who gave us God's infallible Word by the inspiration of the Holy Spirit.
God's Word is useful for teaching, rebuking, correcting, and instructing (2 Timothy 3:16). In the Holy Scriptures, God reveals Himself to us: who He is, what He has done, and what He continues to do. The Bible also teaches us about ourselves and what we must do. The Bible is our primary authority for faith and practice.
God
God is infinite, eternal, and unchangeable in His being, wisdom, power, holiness, justice, goodness and truth. God is one God in three persons: The Father, the Son, and the Holy Spirit. These three persons are one God, equal in substance, power, and glory.
Man
Mankind was created by God in God's image, male and female. God created the first man from the dust of the ground and breathed life into Him. Woman was created out of man to complement and complete the man, with different roles but equal in importance and glory. From these first two people came all of mankind. Man is comprised of body and soul. Mankind was created perfect in righteousness and holiness. God gave mankind authority over His creation, to fill the earth and subdue it.
Man was created to be in community with other human beings and in intimate relationship with the Triune God. Marriage, instituted by God as a relationship between one man and one woman, is intended to be the most intimate human relationship and reflects the love of Christ for His Church.
Sin
Sin is rebellion against the Almighty God. Our first parents sinned against God, and as a result, all of creation was placed under a curse, and all mankind became sinful by nature. We are born sinful. Sin affects all that we think, understand, say, and do. As a result of our sin, we are alienated from God, are in conflict with each other, and deserve God's infinite wrath and curse.
Salvation
God, out of His infinite grace and mercy, has provided mankind a way to be saved from His wrath and to instead be reconciled to Him and become recipients of His grace and blessing. The only means of salvation is the one provided by God Himself: faith in His Son Jesus Christ. God, out of His love for His chosen people, sent His Son to become the perfect sinless man Jesus Christ. Jesus lived a perfect life, died on the cross for His people, and was raised to new life for His people. All people are called to confess our sins and turn away from those sins and to put our faith in the perfect life, death, and resurrection of Jesus Christ. God's Holy Spirit works this faith in God's chosen people, causing a spiritual "new birth", resulting in eternal life.
Jesus
Jesus Christ is the Son of God incarnate, born of a virgin woman, born into poverty and suffering. Jesus is and will forever be fully God and fully man. Jesus is the King of Kings and Lord of Lords and the Good Shepherd who laid down His life for His sheep. Jesus lived a perfect life, died a perfect death as a sacrifice to satisfy God's justice, and was resurrected to give new life to all His people. Jesus ascended into Heaven and now sits at God's right hand, praying for His people. Jesus will return once for all to deliver His people forever and to live in perfect union with them for all eternity.
Holy Spirit
The Holy Spirit is fully God, the Spirit of the Lord Jesus Christ, and the eternal third person of the Triune God. The Holy Spirit was sent by the Father and the Son and was poured out on all the Church at Pentecost. The Holy Spirit dwells in the body of every individual believer and in the Church as whole. The Holy Spirit revealed God's Word to prophets and the human authors of Scripture and also illumines the hearts and minds of human recipients of God's Word today. The Holy Spirit unites us to Christ and works faith and fruit in the lives of believers.
Sanctification
After coming to faith in Jesus, we are commanded to grow and mature in Jesus Christ. This is called "sanctification" or "growing in Christlikeness" or "being made holy". We are told to grow in the grace and knowledge of the Lord Jesus Christ. We are commanded to "put to death" our sin nature and to become more like Jesus. These things are done by the work of the Holy Spirit as God works in us "to will and to work according to His good pleasure." Believers will never be fully sanctified until we are glorified in God's presence after death or when Jesus returns.
The Church
The Church is not a building but the people of God. Scripture refers to the Church as the "Bride of Christ", the "Temple of the Holy Spirit", a "pillar and buttress of truth", and the "household (or family) of God."
We speak of the "visible church" and the "invisible church." The visible church is comprised of everyone who has professed faith in Jesus as their Savior as well as their children. The "invisible church" is the one true Church comprised of all those who have been chosen from all eternity by God for salvation in Jesus Christ and have truly put their faith in Him.
Baptism
Baptism is a sign and seal of our entrance into God's covenant with His people, administered to all who profess faith in Christ and their children.
Lord’s Supper
The Lord's Supper is a sign and seal that we are partakers of Christ's body and blood, with all His benefits, to our spiritual nourishment and growth in grace. In the Supper, we eat and drink ordinary bread and wine (or juice), and at the same time we are spiritually nourished as we spiritually feast on the body and blood of the Lord Jesus Christ. The Lord's Supper is for all who have professed their faith in Christ and are members in good standing of a local church that preaches the gospel of Jesus Christ. Our practice at Zion is to observe the Lord's Supper each week during corporate worship.
Return of Jesus
The Lord Jesus Christ will return once to rescue all His people and to defeat all the Lord's enemies for all eternity. In so doing, He will bring about a new Heaven and a new Earth, in which there is no sin or death or sadness. God's people will live in perfect blessedness with the Lord Jesus Christ for all eternity. No one knows the day or the hour when this will happen except the Father, but it is the Church's responsibility to watch and to wait and to eagerly pray, "Come, Lord Jesus."