These things I have written to you who believe in the name of the Son of God, that you may know that you have eternal life, and that you may continue to believe in the name of the Son of God. I john 5:13
O.K., if you believe in the Lord Jesus Christ you will never have to "defend" yourself.
All persons are sinners, We have ALL fallen short the Glory of God. (read Romans 3:23) you can not lose your salvation. You gained your Salvation as a Gift, not from anything you did. (Ephesians 2:8-9)
Galatians 2:21 states pretty clear that if we become righteous by anything we do, or if we could get to heaven by any other way other than Jesus Christ's death on the cross, it would be in vain.
God will not cast us out and no man can cause us to lose our salvation, We cant lose it ourselves, There is no situation, that can seperate us from God (read Romans 8:38-39)
Your relationship with God is a Father/Son relationship by birth. (read John 1:12-13)
You can find assurance of your salvation in the present (read I John5:11-13) God promiced that if you believe in Jesus, you will have Eternal Life. Your Salvation is not based on your feelings it is based on the factual truth of the Word of God. I John 3:20 tells us that even our heart can't condemn us because God is much greater than that. God knows if you're saved even if you don't. Titus 1:2 is there to teach us that God made a promice,and God Cant lie- So his word is good.
Believe what God has said. (in I John 2:25) He has primiced us Eternal Life.
There are some churches today the teach that we must work to keep our salvation, if we sin after we are born again, we can lose our salvation, or that God casts out his children according to his own whim and pleasure, from the Bible pricipals taught you should understant that these teachings are false.
If you are willing to accept that Jesus Christ was sent to you by God to die on the cross for all of your sins, You will never have to "Defend your life to God".
I am not the best example of someone that is right with God, but I do understand how he works in my life, and I am willing to let him work my life in his way. I dont know if this is what you were looking for in your post, but I hope that someone can use what I have posted, It is my longest post that is not a smart a$$ remark [:D] I would suggest that if any of you want to know more, maybe you could ask Paster Tom in chat, or ETH, they are way better at this than I will ever be.