There are many other things Christians might boast about; going on a missions trip, serving in the church, teaching Sunday school, feeding the homeless, etc. It’s hard to tell if we are doing things for the wrong motives sometimes. Do we serve God to be noticed by others, or do we serve God just to serve God? Ongoing self-examination is good for anyone to do. It is always good to consider why we do what we do. Do we do good things for a boost to our own ego; to feel better about ourselves? Are we like the Pharisees and want other people to notice all the good that we do? What would Jesus say then, we have already received our reward. Jesus said when you give to anyone in any way, “don’t let your right hand know what your left hand is doing. " Do we pray to be seen and heard by men, like the Pharisees did? Or, do we pray because we want to draw closer to God and build our relationship with Him alone? Do we give, and then tell everyone how much we gave and who we gave to, or do we do it without drawing any attention to ourselves? It’s hard to give or to pray or to fast, etc. in secret without telling anyone, because our flesh wants others to know all that we are accomplishing for God. Our flesh wants to brag and boast. Our flesh wants to say, “Look at me! Look at how holy I am!” But, is that really being holy? Paul said, “Am I now trying to win the approval of human beings, or of God? Or, am I trying to please people? If I were still trying to please people, I would not be a servant of Christ. " (Galatians 1:10). That is a good verse to always keep in mind in your Christian walk.
“If you hate, then you are a murderer. . . " and also “Whatever you do (or do not do) for/to the least of these, you do for/to me. " – and He even said: “Love (be kind to) those who hate you. " That is hard to do, especially if they are merciless people who think they are serving God by being harsh and unloving, or such.