Some religious people seem to like money ... too much (1 Timothy 6:6-10).  Standing by the temple offering boxes, Jesus had just criticised the spiritual leaders for demanding money from the vulnerable, particularly widows (Luke 20:46-47).  He saw rich people making a show of how much money they were giving, when a poor widow came to make her offering. Her money made very little noise as it went into the box because she had only given two small copper coins.  But Jesus knew that her gift was the only money she possessed.

The rich people had little difficulty in giving a lot of money.  Even a tithe (10%) left 90% with the giver (Leviticus 27:30-32).  Jesus did not despise the giving of tithes, considering that they were a part of normal godliness, but not the totality of piety (Matthew 23:23).  However, the poor widow gave 100% of her money to the Lord, leaving nothing for herself.  Jesus commented on the difference between these gifts.  

The rich people gave what they could easily afford, and their gift hardly impacted their lifestyle at all.  On the other hand, the widow gave everything, which potentially meant a radical change to her lifestyle: she was then even more dependent on God to provide for her needs.  So, Jesus' comment that the widow had "put in more than all the others" was not based on the amount of money in the box, but on the amount of her love, devotion and sacrifice as well as her confidence that God would continue to meet all her needs.

The way we use our money says a lot about what is important to us.  Giving speaks of love, but the desire to keep for ourselves indicates self-centeredness and lack of trust in the Lord.  Sacrificial giving to the Lord is a wonderful mark of our devotion to Him, provided that it is from our heart and not a people-pleasing response to the demands of others.  As 2 Corinthians 9:7 says, "Each of you should give what you have decided in your heart to give, not reluctantly or under compulsion, for God loves a cheerful giver."  Of course, everything we own belongs to God, and we are stewards of it - we cannot give anything to Him that He has not already given to us (1 Chronicles 29:14); but in keeping our money, possessions, time and talents for our own purposes we might be stealing from Him (Malachi 3:6-10)!