You can survive just fine without finding an altar just yet - divine favor just makes things a little bit easier. You can pray about twice from the get go before your god gets tired of your continued requests and you need to start making sacrifices. Altars are relatively rare but you are bound to find one eventually. Focus on completing the carpenter quest - the reward (if you complete it in the "merciful" way) will already make you more likely to survive. If you find an altar in the VD, great. If you don't, don't worry. You're bound to find one in the next dungeon.
Playing since gamma 10, when necklaces looked like &s. Lithium man. Brass + Lithium. OCG. Illiterate barb. One race and one class to go.