But at times to writers searching for an agent it's like a two step shuffle of queries and rejections. Don't take it personally. An agent's job is difficult and tedious at best. It's like mucking out a barn only once in a great while do you run across something truly precious, but still you wear high boots and gloves.
They may believe in your work but may not be sure of how to sell it...this would be the best option in regards to a rejection.There are several agents blogs about why they accept certain manuscripts and not others, how to query, how to submit and assorted other topics. Check them out.
Above all do not give up. You wouldn't want an agent who only half-believes in your novel. You definitely don't want one you have to pay to even consider representing you. Just like finding a mate for life...the road is long and sometimes very lonely, but when it's right it's fabulous!
I found this satire about how to get an agent. I know plenty of reputable agents and they DO NOT behave this way. It is is funny and not based on actual agent behavior although there are some manuscripts they might want to behave this way about.
Keep writing and loving the Lord. Just don't submit it to this guy!