Is attaining reward and merit conditional on having the intention present at the time of helping others and fulfilling their needs, or is an intention formed after the completion of the act sufficient for that?

Striving to fulfill the needs of Muslims and alleviate their distress is a great act of worship. It has been narrated in the noble Hadith: "Whoever relieves a believer of a worldly distress, Allah will relieve him of a distress on the Day of Resurrection..." And good deeds protect against evil fates. One must persevere in doing good and beware of the whisperings of Satan that cast doubt on intention and sincerity. A Muslim is rewarded for good deeds even if he does not consciously intend to obey [Allah's command].