I say, and with God's help: This statement is not correct. Abandoning prayer out of laziness is a major sin and a grave matter, but it does not lead a person to disbelief. The fasting person who does not pray has a valid fast, for fasting is a complete act of worship and a specific obligation that does not depend on the validity of another obligation. However, acceptance is based on piety, and this knowledge is with God Almighty. And God knows best.