This is a good example as to why we should not believe everything people write on the internet.
This is what the SDA church believes….
What do Seventh Day Adventists Really Believe? - Adventist.org
What you wrote:
1. Trinity - Do not believe in the Trinity.
Fiction
FACT:
What Adventists Believe About the Trinity - Adventist.org
BELIEF 2: THE TRINITY
There is one God: Father, Son, and Holy Spirit, a unity of three coeternal Persons. God is immortal, all-powerful, all-knowing, above all, and ever present. He is infinite and beyond human comprehension, yet known through His self-revelation. God, who is love, is forever worthy of worship, adoration, and service by the whole creation. (Gen. 1:26; Deut. 6:4; Isa. 6:8; Matt. 28:19; John 3:16 2 Cor. 1:21, 22; 13:14; Eph. 4:4-6; 1 Peter 1:2.)
2. They teach and believe that Jesus Christ is MICHAEL the Arch angel. FICTION
FACT-
What Adventists Believe About God the Son - Adventist.org
God the eternal Son became incarnate in Jesus Christ. Through Him all things were created, the character of God is revealed, the salvation of humanity is accomplished, and the world is judged. Forever truly God, He became also truly human, Jesus the Christ. He was conceived of the Holy Spirit and born of the virgin Mary. He lived and experienced temptation as a human being, but perfectly exemplified the righteousness and love of God. By His miracles He manifested God’s power and was attested as God’s promised Messiah. He suffered and died voluntarily on the cross for our sins and in our place, was raised from the dead, and ascended to heaven to minister in the heavenly sanctuary in our behalf. He will come again in glory for the final deliverance of His people and the restoration of all things. (Isa. 53:4-6; Dan. 9:25-27; Luke 1:35; John 1:1-3, 14; 5:22; 10:30; 14:1–3, 9, 13; Rom. 6:23; 1 Cor. 15:3, 4; 2 Cor. 3:18; 5:17-19; Phil. 2:5–11; Col. 1:15-19; Heb. 2:9-18; 8:1, 2.)
We do not believe Jesus is and angle or a created-being, He is the Creator and is called many names in the Bible.
3. They teach that the writings of Ellen G. White are the authority and NOT the Bible.
FICTION
FACT:
The Scriptures testify that one of the gifts of the Holy Spirit is prophecy. This gift is an identifying mark of the remnant church and we believe it was manifested in the ministry of Ellen G. White. Her writings speak with prophetic authority and provide comfort, guidance, instruction, and correction to the church.
They also make clear that the Bible is the standard by which all teaching and experience must be tested. (Num. 12:6; 2 Chron. 20:20; Amos 3:7; Joel 2:28, 29; Acts 2:14-21; 2 Tim. 3:16, 17; Heb. 1:1-3; Rev. 12:17; 19:10; 22:8, 9.)
4. . The SDA teaches a contradictory doctrine of Justification through Faith, in which perfectionism is stressed over faith = WOKS to be saved.
FICTION
FACT
In infinite love and mercy God made Christ, who knew no sin, to be sin for us, so that in Him we might be made the righteousness of God. Led by the Holy Spirit we sense our need, acknowledge our sinfulness, repent of our transgressions, and exercise faith in Jesus as Saviour and Lord, Substitute and Example. This saving faith comes through the divine power of the Word and is the gift of God’s grace. Through Christ we are justified, adopted as God’s sons and daughters, and delivered from the lordship of sin. Through the Spirit we are born again and sanctified; the Spirit renews our minds, writes God’s law of love in our hearts, and we are given the power to live a holy life. Abiding in Him we become partakers of the divine nature and have the assurance of salvation now and in the judgment. (Gen. 3:15; Isa. 45:22; Isa. 53; Jer. 31:31-34; Ezek. 33:11; 36:25-27; Hab. 2:4; Mark 9:23, 24; John 3:3-8, 16; 16:8; Rom. 3:21-26; 8:1-4, 14-17; 5:6-10; 10:17; 12:2; 2 Cor. 5:17-21; Gal. 1:4; 3:13, 14, 26; 4:4-7; Eph. 2:4-10; Col. 1:13, 14; Titus 3:3-7; Heb. 8:7-12; 1 Peter 1:23; 2:21, 22; 2 Peter 1:3, 4; Rev. 13:8.)
We should be careful of the things we say as we are accountable for every idle word. Just a quick search on the Official SDA website on the Statement of Beliefs would have easily cleared up your great misunderstanding of the church teachings.
God bless.