In studying the Bible, we come across some really big words sometimes. Often I'm not sure exactly what they mean. Reading studies on the shorter catechism has helped a lot with that. My usual reaction is, "Ohhh, okay... so that's the word for that". The problem is not a misunderstanding of the thought or principle, but of the words most often associated with them.

Q: What is justification?
A: Justification is the act of God's free grace by which He pardons all our sins and accepts us as righteous in His sight. He does so only because He counts the righteousness of Christ as ours. Justification is received by faith alone.

22the righteousness of God through faith in Jesus Christ for all who believe. For there is no distinction: 23for all have sinned and fall short of the glory of God, 24and are justified by his grace as a gift, through the redemption that is in Christ Jesus, 25whom God put forward as a propitiation by his blood, to be received by faith. This was to show God's righteousness, because in his divine forbearance he had passed over former sins. 26It was to show his righteousness at the present time, so that he might be just and the justifier of the one who has faith in Jesus. - Romans 3:22-26 ESV

We are all alike, in that "we have all sinned and fall short of the glory of God". Where it reads "he had passed over our former sins", that is not to say that He overlooked them or acts as though we never committed them. It means that, through the sacrifice of Jesus, He pardons our sins - we no longer have to pay for them or accept the punishment we deserve. But we have to put our faith in Jesus for His righteousness to be counted to us:

21For our sake he made him to be sin who knew no sin, so that in him we might become the righteousness of God. 2 Corinthians 5:21 ESV

Second, this "free grace" is received totally by faith alone.

9and be found in him, not having a righteousness of my own that comes from the law, but that which comes through faith in Christ, the righteousness from God that depends on faith-- Phillipians 3:9 ESV

There is nothing we can do to earn this gift.  Our good deeds won't earn it. Being seen in the right church won't earn it. Nothing we could do would add to what Jesus has done for us - all we have to do is accept, by faith, that He has actually done it.