Sin of Ananias and Sapphira

One of the saddest events recorded in the Bible is that of the couple: Ananias and Sapphira. They had good desires to give, but by sinful motivation for giving, lost their lives. (Acts 5:1-12) They wanted to imitate Barnabas, give their land to the church and gain reputation. Yet, they did not give all the amount they got through sales, kept a portion. God judged them that both died in the presence of Peter for lying to the Holy Spirit.
1) Contempt: When a person dedicates something for the Lord, it belongs to the Lord. If they take from that portion it is stealing and showing contempt to the Lord. Eli the priest was punished for not restraining his children from showing contempt to Lord and His offerings. (I Samuel 3:13)
2) Hypocrisy: Outwardly, Ananias and Sapphira showed themselves as those who love the Lord, dedicated, sacrificial, generous and spiritual. In fact, they were like white-washed tombs. (Matthew 23:27-28)
3) Lack of faith: They could not trust God. Having a portion of sales would help them to meet their needs in difficult times. Instead of trusting God, they trusted their wealth.
4) Telling lies: They told lies to the Holy Spirit and they were judged.
5) Greed: They had the desire to give sacrificially, but they harboured greed in their heart. Hence, they lusted for a portion of their wealth, which was a foolish idea.
6) Futile image building: They carefully cultivated an image of a generous giver in the eyes of the congregation in the city of Jerusalem. Yet, it was a hype and vanity project.
7) Selfish pride: They were not guided by humility, instead by pride. They were selfish in seeking praise of fellow-believers rather than approval by God.
The first century church had a model of not giving properly. It is similar to that of giving Cain. (Genesis 4) Like Cain, this couple also wanted to give to God in their own terms not as required by the Lord.
What is my motivation for giving unto the Lord?