ERROR : Invariant Violation Text Strings must be rendered within a component

I am the beginner of react native. I have a problem but i don't understand what i am doing wrong.

This is my code:

import React, {Component} from 'react';
import {
  SafeAreaView,
  StyleSheet,
  ScrollView,
  View,
  Text,
  StatusBar,
} from 'react-native';

import {Button,Input} from 'react-native-elements';
import firebase from './screens/firebase';

console.log(firebase.name);
console.log(firebase.database());

class App extends React.Component
{

constructor(props)
{
  super(props);
  this.state = ({
    name:'',
    email : '',
    Password : '',
    id:'',
    phone:'',
    })
}

signup = (name,email,Password,id,phone) =>
{
  try
  {
    firebase.auth().createUserWithEmailAndPassword(name,email,Password,id,phone)
  }
  catch(error)
  {
    console.log(error.toString())
  }
  alert('signUp Successful')
}

  render()
  {
    return(
      <View style = {styles.container}>

      <Input
        placeholder='Enter Name'
        onChangeText={(name) => this.setState({name})}/>

      <Input
        placeholder='Enter Email'
        onChangeText={(email) => this.setState({email})}/>

      <Input
        placeholder='Enter Password'
        onChangeText={(Password) => this.setState({Password})}/>

       <Input
        placeholder='Enter id'
        onChangeText={(id) => this.setState({id})}/>

        <Input
         placeholder='Enter Phone'
         onChangeText={(phone) => this.setState({phone})}/>

    <View style={{marginTop : 40,flexDirection : 'row'}}>

     <Button
       title="Sign UP"
       onPress = {() => this.signup(this.state.name,this.state.email,this.state.Password,this.state.id,this.state.phone)}/>
      </View>
     </View>
      );
  }
}


const styles = StyleSheet.create({
  container :
  {
    flex : 1,
    justifyContent : 'center',
    alignItems : 'center',
  }
});

export default App;

There is a compiler error which reads :

Invariant Violation: Text Strings must be rendered within a component

Where am I making a mistake? I have been dealing with this problem for a long time, thanks for your help.