One of the effects of being saved by Jesus Christ and being made a new creation in Him is a care about things which did not previously seem worthy of care. There are many areas that could be highlighted, but for the sake of holding interest I will pick three: providing for the less fortunate, accountability and evangelism.
Jesus wants those who claim His name to give food to the hungry and clothe the naked. He even goes as far as to claim that in the last day God will bring these things to remembrance for you and say,
Assuredly, I say to you, inasmuch as you did it to one of the least of these My brethren, you did it to Me. (Matthew 25:40)
Not only will God see our love by this standard, but He will see our lack of love by this as well,
...inasmuch as you did not do it to one of the least of these, you did not do it to Me. (Matthew 25:45)
As a believer in the resurrection of Christ and a temple for the permanent indwelling of the Holy Spirit, these kinds of statements should stir us up. I am continually being convicted of the lack of effort I make to obey these commands. How often do we really go out into our community and provide for the less fortunate? We can't make the argument that we don't know where to find these people, for they are all around us. We also can't make the argument that we are too busy because Jesus' commands outweigh life's demands.
If you claim the name of Christ, if you wear the Cross around your neck like you have something to stand up for, then put it into practice. James says that if we only hear the Word and don't practice it, we have deceived ourselves (James 1:22). Jesus tells us where our hearts should be and if you are truly in submission to Him, He will reverse your apathy in this area.
Before we were ever Christians, we had no reason to be held accountable. There was nothing wrong with our sin in our minds, so why let it be known or make strides to put it to an end? Now that we have seen our wickedness and been saved by grace through faith in Christ, we should put to death the deeds of the flesh (Romans 6 is wonderful on this). Part of this is sharing weaknesses with trustworthy brothers or sisters to allow them to pray for specific areas.
In doing this, we are not only helping ourselves spiritually, but we are strengthening our relationships with other believers in a God-honoring way. If you do not have a fellow believer or group of believers with whom you regularly meet with to confess and pray with, I highly recommend it. Doing this is truly glorifying to God and allows the Spirit to mature you in the Lord.
Evangelism! Not all of us are evangelists, per se, but we are all called to this:
...always be ready to give a defense to everyone who asks you a reason for the hope that is in you, with meekness and fear (1 Peter 3:15)
What does that mean? It means that we should all be sharing our faith in one way or another. If you have the gospel and have been withholding it from those who do not believe, how should you feel? I'll let the Spirit deal with that.
For whom did Christ die?
If you're a believer, I know that God has given you a passion to reach the lost and He continually works on us in this area. The gospel of Christ has reversed our apathy concerning those who do not know Him and it is our duty to follow up on that with an active response that aims toward sharing the good news.
Be encouraged. Get energetic and enthusiastic.