Can we do the things that God wants in a way that doesn't put him first? Yes, we can. This is exactly what 2 Chronicles tells us King Amaziah did. On the outside, he was doing all the right things, but his heart wasn't in it. His heart was on his own agenda, his own desires.
A heart turned towards God, and towards serving others, is one that is wide open to God's blessings. Our motives for doing things are, so often, mixed. How often have we thought, 'This will make me look good. I wonder how many people saw me do that?' The challenge for us, then, is this: 'Blessed are the pure in heart, for they will see God' (Matthew 5:8 NIV). In our service, if we strip back our self-focus, we clear the way to see him more clearly and let his blessings in. It's always good to consider where our heart is when we give.
The truth of the matter is that we're not giving to a God with a ticklist. 'God loves a cheerful giver' (2 Corinthians 9:7 NIV). He really does. The giving of our money, time and energy should originate from gratitude for his love for us. That's a win-win for everyone involved - we don't need to impress anyone, and our lives become bigger.
So what now? Consider this thing called generosity. Assess your giving (this can be money, time or skills) and your motives. Pray, asking God to set you heart right where he needs to.