II Samuel 12:20 Then David arose from the earth, and washed, and anointed himself, and changed his apparel, and came into the house of the LORD, and worshipped: then he came to his own house; and when he required, they set bread before him, and he did eat.
Worship is not something that we do when all is going well. We are to worship in the good times as well as the bad times.
David has just lost his child. He has asked God to save his son but God has refused.
Can it be real worship if you only magnify the Lord when He does what you want? We must prostrate ourselves before Him in the good as well as the bad.
That is true worship. After having begged God for a week with fasting and prayer David first went to the house of the Lord and worshipped which almost assuredly means that he gave an offering, praised the Lord, and thanked Him.
As a missionary you are going to find that many things just do not work out the way you wanted them to or had figured them to work out. There will be no church meetings to encourage you. You must know how to worship God before you start out or you will never make it.
Learn to give thanks in all things now. Learn to love and serve Him no matter how things turn out. He is God you are but the servant.