The Word of God is the foundation of our faith, the anchor of our Salvation. What the Word says is the TRUTH. We do not rely on the what people may say to bend the word of God to their lifestyles, we rely on what the Word of God says because it is eternal, unchanging, and powerful.
The Word says we are saved by Grace (Ephesians 2:8-9) when we believed that it is only through the sacrifice of Jesus on the Cross that we received forgiveness for our sins and therefore become children of God by faith (John 1:12). Not "perfect" children, but children of God.
Sanctification starts at the moment of Salvation when we are indwelt by the Holy Spirit (Titus 3:4-7 and Philippians 1:6). God Who began the good work in us will carry it on to completion. God Himself confirmed it with an oath, in which it is impossible for God to lie (Hebrews 6:18) and "We have this hope as anchor to our soul, firm and secure." (Hebrews 6:19).
Jesus Christ promised to be in us (John 14: 20) and He will give us the Holy Spirit, the Counselor, Who will guide us and teach us all things (John 14:16-17; 26 & John 15:26). God Himself gives the Holy Spirit as a deposit and as a seal (2 Corinthians 5:5). God said He will never leave us nor forsake us (Joshua 1:5). "The Spirit testifies with our spirit that we are God's children." (Romans 8:16). We do not have to "ask" for the Holy Spirit, we receive Him at Salvation and we pray to be filled with the Spirit.
"Having believed, you were marked with Him in a seal, the promised Holy Spirit, Who is a deposit guaranteeing our inheritance until the redemption of those who are God's possession - to the praise of His glory." (Ephesians 1:13-14)
"And in Him you too are being built together to become a dwelling in which God lives by His Spirit." (Ephesians 2: 22)
When we were born-again we become "new creations" (2 Corinthians 5:7) because as the verses in Philippians 1:6) God has began His work in us, He will be faithful to complete it (1Thessalonians 5: 23-24)
God is the One Who works in us to will and to do according to His good purpose. (Philippians 2:13)
We do not lose our salvation when we die with sin because Jesus Christ assured us in His Word :
"For God so loved the world and gave His Only begotten Son that whosoever believes in Him shall NOT PERISH but have ETERNAL life. For God did not send His Son to condemn the world, but to save the world through Him." (John 3:16-17)
"For My Father's will is that everyone who looks to the Son and believes in Him shall have eternal life, and I will raise him up to the last day." (John 6:40)
"I give them eternal life, and they SHALL NEVER PERISH; no one can snatch them out of My hand. My Father Who has given them to Me, is greater than all, no one can snatch them out of My Father's hand." (John 10: 28-29)
We have crossed over from death(condemnation/judgment) to life -everlasting peace and fellowship with God.
"I tell you the truth, whoever hears my word and believes Him Who sent Me has eternal life and will not be condemned; he has crossed over from death to life." (John 5:24) We do not lose Salvation, we lose our rewards and crowns.
We are completely saved - nothing in all creation can separate us from the love of God in Christ Jesus (Romans 8:38-39) not even our past sins or future sins. Jesus Christ Himself intercedes in our behalf:
"Therefore, He is able to save COMPLETELY those who come to God through Him because He always lives to intercede for them." (Hebrews 7: 25)
God is able to save us and keep us. "To Him Who is able to keep you from falling and to present you before His glorious presence WITHOUT FAULT and with great joy - to Him be glory, majesty, power and authority, through Jesus Christ our LORD, before all ages, now and forevermore! Amen." (Jude 24).
"Praise be to God and Father of our LORD Jesus Christ! In His great mercy He has given us a new birth into a living hope through the resurrection of Jesus Christ from the dead, and into an inheritance that CAN NEVER PERISH, spoil, or fade -kept in heaven for you." (1 Peter 1: 3-4)
Jesus Christ is the Author and PERFECTER of our faith - nothing we can do will change that - He perfects our salvation just as He promised (Hebrews 12:2) We are saved because of Jesus Christ, not because we are righteous, even if we are righteous in our own ways, when we die. We are saved because of CHRIST'S RIGHTEOUSNESS, not ours.
Today, if you are still not sure of your Salvation, ask yourself - is there a verse in the Bible that says "After you have trusted in Jesus Christ - you are no longer saved IF you have sin when you die..."? Look for it - it is not there.