Great idea for a Topic!
1.) Salvation and maintenance thereof requires only two things:
Matthew
22:37 Jesus said unto him, Thou shalt love the Lord thy God with all thy heart, and with all thy soul, and with all thy mind.
22:38 This is the first and great commandment.
22:39 And the second [is] like unto it, Thou shalt love thy neighbour as thyself.
Notice that this does not allow for any man to get or stay saved by doing any magical 'work' or ordinance or sacraments. It is all based on faith and love. Jesus did all the heavy lifting on the Cross.
Ephesians
2:4 But God, who is rich in mercy, for his great love wherewith he loved us,
2:5 Even when we were dead in sins, hath quickened us together with Christ, (by grace ye are saved
2:6 And hath raised [us] up together, and made [us] sit together in heavenly [places] in Christ Jesus:
2:7 That in the ages to come he might shew the exceeding riches of his grace in [his] kindness toward us through Christ Jesus.
2:8 For by grace are ye saved through faith; and that not of yourselves: [it is] the gift of God:
2:9
Not of works, lest any man should boast.
2:10 For we are his workmanship, created in Christ Jesus
unto good works, which God hath before ordained that we should walk in them.
Verse 9 shows us that no man can boast that He acquired salvation by his own hand.
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2.) Now we see verse 10... Here we see how 'other things' fit into the picture. God uses us to produce good work through the guidance and power of His Spirit. We are vessels and tools in the master's hand.
Some things we do are simply ordinances and sacraments we do to remember what He did for us. These things are not required for Salvation, but can be profitable for understanding and growth if kept in their proper place.