The Gospel reading from Luke 14 at Mass: On a sabbath Jesus went to dine at the home of one of the leading Pharisees. He said to the host who invited him, "When you hold a lunch or a dinner, do not invite your friends or your brothers or sisters or your relatives or your wealthy neighbors, in case they may invite you back and you have repayment. Rather, when you hold a banquet, invite the poor, the crippled, the lame, the blind; blessed indeed will you be because of their inability to repay you. For you will repaid at the resurrection of the righteous."
The lesson is clear. Love but do not expect repayment and you will be repaid by God. Again, it's the selfless way of building up treasures in heaven. Basically, the more we empty ourselves, the more God replenishes us.