Because of your reply, let me go a little different direction.
The most important thing in a Christian's life is his faith in Christ.
Now faith is the substance of things hoped for, the evidence of things not seen. Hebrews 11:1
...he that cometh to God must believe that he is, and that he is a rewarder of them that diligently seek him. Hebrews 11:6
If any of you lack wisdom, let him ask of God, that giveth to all men liberally, and upbraideth not; and it shall be given him. But let him ask in faith, nothing wavering. For he that wavereth is like a wave of the sea driven with the wind and tossed. James 1:5, 6
For by grace are ye saved through faith; and that not of yourselves: it is the gift of God. Ephesians 2:8
For ye are all the children of God by faith in Christ Jesus. Galatians 3:26
But continue thou in the things which thous hast learned and hast been assured of, knowing of whom thou hast learned them; And that from a child thou hast known the holy scriptures, which are able to make thee wise unto salvation through faith which is in Christ Jesus. 2 Timothy 3:14, 15
I know it is not popular to talk about sin in this day an age. People get offended by the mere mention of it, but to not understand about sin and how it separates us for God, will not allow people to understand what the true heart of God is and why salvation is needed.
...The time is fulfilled, and the kingdom of God is at hand: repent ye, and believe the gospel.
Mark 1:15
And they went out, and preached that men should repent. Mark 6:12
The Lord is nigh unto them that are of a broken heart; and savedth such as be of a contrite spirit. Psalms 34:18
He healeth the broken in heart, and bindeth up their wounds. Psalms 147:3
...for I am not come to call the righteous, but sinners to repentance. Matthew 9:13
I believe we all have the same opportunity to be resurrected into a new glorified body. However not all want what Jesus has offered us. They will not be given the gift of everlasting life....even though it is available to them. Some will foolishly ignore the call of God and live their lives as they choose...not being led by God. Those who reject God will not be given the same opportunity to receive from God. So, not all will be resurrected and united with Christ....in this life or the next.
God loves each person and wants all to be saved. After all He gave them His own breath of life...but we all must make a decision to believe and follow Jesus. Eternity starts now for a Christian...not just after he dies. If we have His Spirit living within us when we begin that spiritual journey now and without hesitation.
Who gave himself for our sins, that he might deliver us from his present evil world, according to the will of God and our Father: Galatians 1:4
Hebrews 9;28 So Christ was once offered to bear the sins of many; and unto them that look for Him shall He appear the second time without sin unto salvation.
The most important thing in a Christian's life is to have faith in Him and ask God for forgiveness so we can start clean. Only Jesus can make us clean.
Any Atheist can do good works, but it counts as nothing in the after life...only faith counts. However an Atheist may receive praise and reward in this life and for some that is all that is important. For a Christian, we are saved by faith, yet our works that we do as a saved person, are like jewels in a crown. They are remembered by God and our praise is given by God and not by man.
Matthew 6:1 "Be careful not to practice your righteousness in front of others to be seen by them. If you do, you will have no reward from your Father in heaven.
So even Christians need to be careful that we do good works for the right reasons and with the right heart for doing it. Doing it just to be seen doing it will count for nothing in eternity, even if man may receive praise here on earth.
Christians do believe in going good in the world, but the message of salvation must come first and foremost...it can never come second. If we do not emphasize faith first, then the rest is meaningless....for what good is having 80-90 or so years of life and then nothingness or Hell as many believe? Atheist seem happy with that short amount of time. But we are given the option to live forever if we choose Christ to lead us into everlasting life.
So please don't think all Christians sit on their backsides and do nothing in the world just because they spend their time sharing the gospel. Most just don't talk about it because they want their reward in heaven, where it counts the most. However, we are to preach the gospel boldly and not be ashamed.